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Calaméo - Bobcat , B Skid Steer Loader Service Repair Manual DOWNLOAD
Auxiliary detent has a inside depth of 1. NOTE: Carefully remove the centering spring bolt, because there is spring pressure.
Remove the front and rear O-rings. NOTE: It is not necessary to remove the spool from tha bore completely on the counter-bored valve with a bushing 1Aj. Install the valve spool into the control valve from the rear of the control valve. Push the valve spool back into the control valve until it is even with the rear machined surface of the control valve. Put grease on the jaws of the detent tool. Install the centering spring and the other spring cap on the spool and tighten the adapter to in.
The tilt and rear auxiliary spool have a centering spring. Use the following procedure to disassemble and assemble the center mechanism for either spool. Remove the screws securing the cap Assembly: Tighten the screws to in. Assembly: Tighten the centering spring bolt to 9 'lOO in. Centering Spring IRemove the spool and the front and rear a-rings from the bore.
Bushing Early Models 5. Spring Cap Adapter 'nstall the front O-ring in the groove. Install the valve spool into 3. Spring Cap 7. Bolt the valve from the rear of the valve. Push the spool into the valve just far enough so the rear a-ring can be installed. Push the spool back into the control valve until it is even with the rear machined surface of the valve. NOTE: Make sure that all the air is removed from the system before beginning the test.
Air In the system can give an inaccurate test. Lift and block the loader See Page 1- 2 for the correct procedure. When the tester is connected this removed from the hydraulic pump Ii!. DO NOT close the flow restrictor, on the tester, all the way.
NOTE: Make sure that the restrictor valve on the tester is fuly open. Start the engine and run at idle RPM. Make sure the tester is connected correctly. If no flow is indicated on the tester, the hoses are connected wrong. Increase the engine RPM to full. DO NOT exceed system relief pressure. Use the right steering lever to put the auxiliary hydraulics into the detent position. Record the highest pressure and flow at full RPM. A low percentage may indicate a failed hydraulic pump or it may be caused by air in the system.
Make sure that all the air is removed from the system. The system relief pressure must be per specification before the test is run. Remove the port block from the hydraulic pump See Page 2 - 51 for the correct procedure. Remove the two mounting bolts 1iJ. Installation: Tighten the bolts to 25 ft. Remove the bOlts from the pump IRI. Assembly: TIghten the bolts to 23 ft. If the ball and spring are instaled in the wrong port.
Only one baD and spring must be instaHed on the high pressure side of the pump or the lower port as it Is attached to the hydrostatic pumps. Inspect the drive gears Check the bearing points and seal area for rough surface and wear. If the shaft measures less than 0. Check the 1. If the bearings are more than 0. Oil grooves in the bearings at both housings must be in alignment with the dowel pin hole and 0 apart. This put the oil grooves closest to the correct dowel pin.
The tools listed will be needed to do the following procedure:. Air in the system can give an inaccurate test. Uft and block the loader See Page for the correct procedure. Raise the operator cab See Page 1- 7 for the correct procedure. Connect the jumper start switch See Page for the correct procedure. Connect the inlet hose of the tester to the outlet of the pump IAJ. Connect the outlet of the tester to the hose which was removed from the pump [Al. Disconnect the hose which goes to the port block at the hydraulic pump.
Put plugs in the hose and the fitting on the pump. Disconnect the hose which goes to the port block on the hydraulic pump. Plug the hose and the fitting on the hydraulic pump. Large Section of the Pump Only: Disconnect the outlet hose from the pump Connect the inlet hose of the tester to the outlet of the pump [iJ. NOTE: Make sure thet the restrictor valve on the tester is fully Be careful when turning the flow control restrictor at open. When the tester is connected this way there is no reUef valve In the system.
Make sure that the tester the flow restrictor, on the tester, aU the way. If no flow is indicated on the tester, the Ihoses are connected wrong. Do not exceed system relief pressure.
Large Section of the Pump Only: Use the right steering lever to engage the auxiliary hydraulics. Record the highest pressure land flow at full RPM. A low percentage may indicate a failed hydrauliC pump. Make sure that all the air is removed form the system.
Raise the lift arms and have a second person install a lift arm stop See Page for the correct procedure I. Clean outside of aU assemblies before beginning repairs. Remove the mounting bolts from the pump flange IAI. Turn the pump so the inlet fitting at the bottom is to the side and slide the pump from the hydrostatic pump I!
Assembly: Make sure the round key Item 1 is in position and engages with the small drive gear slot. Inspect both drive gears and idler gears at bearing points and seal area for rough surfaces and wear. It Always use new O-rings and back-up washers when assembling the bucket position valve.
Clean outside of aa assemblies before beginning repairs. Remove the filter removal tool from the filter I! Particles trapped by the filter may drop and enter the system. Always check the port block for debris and clean the bore. Install the spring, filter and sleeve on the tool! Removal and Installation J Raise the operator cab. Remove the front. Clean outside of aU assemb6es before beginning repairs.
Use plugs and caps to cover open. Disconnect the high pressure hoses at the hydrostatic pumps and remove them from the loader [! Loosen the clamp at the outlet hose for the reservoir I! NOTE: It may be easier to disconnect and remove the hose from the reservoir at the hydraulic pump.
After installing the pedal. If the linkage bar is to be removed. Check the pedal lock linkage so it is free and lock the pedals. Check that the tab goes into the slot at the lock If not. W Page Number. Repairing the Steering Levers Steering Linkage Adjustment The following troubleshooting chart will help to locate and correct problems which are most common.
Many of the recommended procedures must be done by authorized Bobcat Service Personnnel only. No drive on one side, in one direction. No drive on one side in both directions.
The loader does not move in a straight line. The hydrostatic system is overheating. The oil light comes "ON". The hydrostatic system has a fluid leak. The steering linkage needs adjustment. The high pressure replenishing valve s are defective.
The shuttle valve in the hydrostatic motor has a defect. The balance plate in the hydrostatic motor seals is defective. The hydrostatic pumps have a defect. The final drive chain is broken.
The hydrostatic motor has a defect. The tires do not have the correct air pressure. The tires are not the same size. The hydrostatic fluid is not at the correct level. The oil cooler has a restriction. The temperature switch is not operating correctly.
The control valve is not operating correctly. The engine is not being operated at the correct RPM. One of the switches is defective. There is low charge pressure. Fluid Replacement. Install new teflon bushings into the steering levers U! Check the pivot bearings and replace as needed. Move the left steering lever until the tires do not turn neutral. Adjust the rear pintle bar so that the bar is tight against both lobes of the pintle lever and the transmission is still in neutral [g.
Move the left steering lever backward and forward and let the transmission return to neutral. If the transmission does not go back to neutral, repeat the adjustment.
Move the right steering lever until the tires do not move neutral. Adjust the front pintle bar so the bar is tight against the lobes of the pintle lever and the transmission is still in neutral mi. Move the right steering lever backward and forward and let the transmission return to neutral. If the transmission does not return to neutral, repeat the adjustment. Installation: Install the key in the pintle shaft [j?
Tighten the pintle lever bolt to ft. Raise the lift arms and have a second person install a lift arm stop See Page for the correct procedurel. Remove the brake pedal rru. Remove the hydraulic foot pedals and linkage See Page 2 - 60 or for the correct procedure. Remove the hand grip by plugging the hole in the bottom of the steering lever and using air pressure to remove the hand grip both sides [Q].
Install new teflon bushings when installing the two steering assemblies together I until the tires do not turn neutral. Push the rear bar against both lobes of the lever with transmission in neutral. Tighten the rear bar bolts to 28 ftAbs. I Move the steering lever, for the front arm, until the tires do not turn neutral.
Move both steering levers backward and forward and let the transmission return to neutral. If the transmission does not return to neutral, repeat the adjustment again. Installation: Install new lock nuts and tighten to 23 ft. Installation: Turn the centering spring bolt Item 1 into the rear bracket until the spring measures Item 2 3. Installation: Install the key in the pintle shaft.
TIghten the pintle lever bolt to 18 - 20 ft. Remove the bolts from the lobes on the pintle lever IIJ. Installation: Tighten the bolt to 25 - 28 ft. Press the rubber bushing into the pintle lever, using two sockets and a vise [QJ. A hydraulic servo control cylinder Item 1 is used to stroke each hydrostatic pump pintle lever [AJ.
The hydraulic servos are controlled by steering levers and the fluid to activate them comes from the charge circuit [AJ. Remove the bolt from the servo spool Item 4 and steering linkage both sides [AJ. They will turn whenever the pump is not centered. Adjust one side at a time. Adjust the centering spring mechanism for the steering lever so that there is no free play.
Loosen the two jam nuts Item 1 and turn them in or out When there is no more free play in the centering spring mechanism, lock the jam nuts together. Position the steering lever by loosening the jam nut Item 2 and turning the centering rod Item 3 in or out of the ball joint When the steering lever is in a perpendicular position, lock the jam nut Item 2 Check the centering spring mechanism again to make sure that the adjustment no free play has been maintained.
Turn the jam nuts until there is no free play and tighten the jam nuts. Start the engine and run at low idle. They will tum whenever the pump is not centered.
Stroke the servo spool forward and backward allowing it to return to neutral each time. Repeat this several times. If wheel creep is still present, repeat Step 9. Connect the steering linkage to the servo spool. NOTE: The servo spool has a neutral band of approximately 0.
Tum the servo spool so that it is positioned in the center of the neutral band. Stroke the steering lever forward and backward letting it return to neutral by itself several times. If the wheels do not creep the adjustment is completed. Repeat the Steps 3 through 15 to adjust natural for the other side of the loader. To remove, install or repair the centering spring mechanism, use the following procedure:. Remove the lock nuts lID. Installation: Tighten the lock nuts to 16 - 20 ft. Installation: Before tightening the bolts and nuts, install the spring rod and align the rod end hole and the hole in the pintle lever Iru.
I Remove the centering spring mechanism Page I See Page for neutral adjustment of the servo controls and steering linkage. B B Remove the cap from the servo housing. Clean and inspect all the parts for wear or damage. Replace the parts as needed. Remove the three screws from the pintle lever arm! Installation: Tighten the screws to 60 - 65 in. Re-torque several times until screws stay at 60 - 65 in.
Put loctite PIN on the inside diameter of the hub. Make sure the key is in the slot of the pintle lever shaft and the hub is aligned [! The hydraulic servo system is controlled by the steering levers and the fluid to activate them comes from the charge circuit. Loosen the two jam nuts and turn them in or out. NOTE: If there is any free play in the centering spring mechanism, the correct adjustment of positive neutral can not be obtained.
When the steering lever is in a perpendicular position, lock the jam nut. Connect the Remote Start Switch Page Turn the spool in or out to find the neutral band in the servo control cylinder rnJ. Tighten the jam nut. Loosen the jam nut connector rod end. Turn the rod in or out until the bolt is a frop fit in the pintle steering linkage J.
Install and tighten the lock nut. Make a final adjustment on the clevis threaded rod [! Tighten the clevis jam nut. The steering lever centering should position the spool near the center of this neutral band when the pintle levers are positioned at absolute neutral by their centering springs. If the wheels do not creep the adjustment is correct. I The remove and disassemble the steering lever centering spring mechanism, See Page SIN thru for the procedure.
I To remove and disassemble the spring mechanism, See Page SIN thru , the photo's may look different but the procedure is the same lID. I To remove and install the hydrostatic pump pintle arm See Page SIN thru , the photo's may be different by the procedure is the same lID. If the engine is running. Before making any adjustments to the loader. Start the engine with the remote start switch and increase the speed to RPM See Page for the correct procedure.
Put the steering lever in neutral position to see if the wheels creep. Move one steering lever as far forward as possible to take the forward wheel RPM reading.
Move the same lever as far back as possible to take a reverse wheel RPM reading. To remove the free play, adjust the hydrostatic pump centering '"'" spring by loosening the jam nut Item 1 and turning the adjusting nut in or out [QJ. Start the engine with the remote start switch and increase the speed to RPM See Page for the correct procedurel. Move the servo control spool back and forth several times to find the width of the neutral band. NOTE: Adjustment to the hydrostatic pump linkage rod Item 1 is necessary only if wheel creep is present [g.
NOTE: The mid point adjustment is a preliminary adjustment and may need to be adjusted again. NOTE: Freeplay will exist in the centering spring adjusting rod if the adjusting nut is too loose, or in the centering spring bushing if the adjusting nut is too tight. Turn the adjusting nut in or out to adjust the centering spring mechanism so there is no freeplay [g. Loosen the jam nut Item 1 on the steering lever linkage rod [Q].
Turn the rod in or out until the steering lever is straight up and down and tighten the jam nut [Q]. Recheck the servo control spool neutral band center position and the hydrostatic pump linkage adjustment.
NOTE: It may be necessary to alternate from the servo spool adjustment to the hydrostatic pump linkage adjustment to stop the wheel creep completely. To make a final check of the wheel creep, pull the steering lever all the way forward and let the lever snap back into neutral IAJ.
Repeat the lever snap back procedure 3 to 4 times in both forward and reverse direction. When the steering linkage adjustment procedure is completed, it is necessary to adjust the forward wheel RPM for the right and left wheels. Take a wheel speed reading on both left and right sides rm. If the two sides are different, adjustment is needed. A mechanical stop should be installed on the side which has the faster of the two readings.
With the engine running at RPM, push the steering lever lever on the fast side as far forward as possible.
Install a mechanical stop on the steering lever centering mechanism slow side IQI. With the engine running at RPM, push the steering lever lever on the slow side as far forward as possible.
Turn the mechanical stop in until it just makes contact with the spring mechanism as shown IQI. NOTE: Clean the outside of the motor before disassembly.
Keep all the parts clean. Remove the four bolts from the motor lru. Assembly: Tighten the bolts to 65 - 70 ft. Lift the valve housing straight up. If done carefully, the springs and balance plate w ill stay on the valve.
Use a punch, through the housing and remove the poppet, spring, O-ring and plug from the other side of the housing [g. I Assembly: Make sure all the parts are cleaned and check for wear. Remove the inner seal from the balance plate Assembly: Put grease on the inner seal and install as shown NOTE: Always use new a-rings when assembling the hydrostatic motor. Check the valve plate, valve and balance plate for scratches. The timing of the motor controls the direction of rotation of the Anyone of 6 Ports drive shaft of the motor.
The timing parts are as follows: Open to Outside of Valve. Find the largest opening between the geroler star and the geroler ring and mark the outside of the geroler ring at this point. Align the two drain holes and the three pressure holes in the geroler ring with the same holes in the mounting flange and install the geroler assembly. Align the drain hole in the valve plate with the drain hole in the geroler.
Install the valve plate with the O-ring toward the geroler. Pressure Relief Hole 3 Install the valve plate. Install the valve on the valve plate.
Make alignment with one of the side openings with the mark on the geroler. Turn the valve clockwise a small amount until the teeth on the valve drive engage. Make sure to connect the high pressure hoses to the correct ports of the hydrostatic pumps and motors rru. Front Of Loader. If there is a loss of drive in one direction, to one side of the loader, use this procedure to check the valves:.
Remove the high pressure relief valves from the top and bottom and switch them around [ID [Q]. Installation: Tighten the bolts and nuts to 23 ft. See Page for neutral adjustment.
Remove the steering mechanism and pintle arms from the hydrostatic pumps See Page 3- 7 or for the correct procedure. Installation: See Page or for the neutral adjustment. Disconnect the high pressure hoses at the hydrostatic pumps both sides [Q]. I Disassembly and Assembly. Clean outside of an assemblies before beginning repairs. NOTE: The hydrostatic pump front and rear pump internal parts are the same. Some of the external parts are different and the copy will list the different procedures.
B "o B o o Remove the bolts from the center section. Put your hand under the rotating group and turn the pump housing around so the rotating group will slide into your hand. Remove the seal. Remove the snap ring and spacer [QJ. Remove the bearing from the pintle shaft IAJ. Assembly: When installing the bearing, make sure the number side of the bearing is toward the outside. NOTE: Keep all the parts for one pump separated from the parts for the other pump. Inspect the input drive shaft, bearings and races for wear and damage to the shaft splines!
End play must not exceed 0. The bearings in the center section and housing only have to be removed if they are loose and show wear. Use a press to remove and replace the bearings. Inspect the flat surface of the sections. The finish must be smooth and free of grooves.
Inspect the camplate for wear. If grooves can be felt with a fingernail, replace the camplate. Inspect the rotating group for the following: Check each piston in its bore. The piston must move freely. All the pins must be the same length and must not be bent. Check the piston shoes for scratches. Measure the thickness of each shoe. Within 0. Inspect the shoe plate for wear or cracks. If there is any defect in the rotating group, the complete unit must be replaced.
Clean all the parts in solvent and use air pressure to dry them. N DO NOT use cloth or paper because small pieces of material o can get into the system and cause damage. DO NOT use sandpaper or a file to remove scratches. The loader can be moved for a short distance at a slow speed if it is unable to do so under its own power, use the following procedure to install the tow valve kit:. Install the nut to hold the spacer in place. Push the spacer fully to the left end of the hole.
MC 4. Install the bolt through the spacer Item 4 at the rear of the tool main frame l. Loosen the pump mounting bolts. Slide the tool shaft forward and rotate until its aligned with the pump coupler.
Tighten the pump mounting bolts. Pull the tool shaft from the pump splines and check alignment by sliding the tool shaft forward onto the pump shaft. Remove the alignment tool. Engine Mounting. Use p'lugs and caps to cover open ports. Make sure to install the correct switch if it is replaced See Parts Microfichel. When the brake is in good condition and adjusted correctly. Loosen the nut Item 1 and turn the linkage rod to adjust the brake pedal.
NOTE: If the correct adjustment cannot be obtained by turning the brake linkage rod. Loosen the bolt at the brake lever. Do not remove the bolt Using pry bar and hammer. Remove the bolt and lever. Turn the cam pin counterclockwise until the brake pucks make contact with the brake discs.
Installation : Align the brake discs so they are centered between the brake pucks [Q]. Remove the brake discs lID. Check the brake disc for damage. Replace the discs as needed. DO NOT grind the discs. Installation: Put Loctite on the bolts and tighten to ft. Check the pucks for wear or damage.
The pucks can be turned 0 and the smooth side used again. NOTE: The removal and installation of the four axles use the same procedure. NOTE: The following procedure will work for both the front and rear axles, but for the rear axles the hydrostatic pumps will have to be removed See Page for the correct procedure.
Put a wrench on the bolt at the sprocket; front , rear Loosen the bolt inside the chaincase at the sprocket by turning at the axle hub. Push the axle out until the ram jack is at the end of the stroke.
Add a spacer and push the axle out again. Repeat this procedure until the axle is out of the sprocket. Remove the sprocket from the chaincase. Install the bearing cup puller tool into the axle tube 1m. Remove the bearing cup from the axle tube. Make sure not to damage the axle. Clean and check all the parts for wear and damage. Press only on the inner race of the bearing. This will also position the wear ring correctly.
NOTE: Pack the inner and outer axle bearing with grease before installing the axle assembly. NOTE: The long part of the sprocket hub goes toward the inside for the front axle and the outside for the rear axle. Install the spring over the axle tube [A]. Put the installation tool in contact with the axle tube. Install the washer and bolt inside the chaincase and pull the axle into position. Remove the spring from the tool.
Remove the outer halves of the tool [OJ. Remove the inner halves from the axle [0]. Tighten the sprocket bolt to the correct torque. Check the axle end play. It must be between 0. NOTE: Check the chain for the connector link. If there is no connector link, make separation of the drive chain at any link.
Put the drive chain over the reduction gearcase sprocket and pull the ends out and above the chaincase. Tighten the chain link press to ft. Center the reduction gearcase between the front and rear drive chains. Tighten the bolts to ft. Remove the steering levers See Page or for the correct procedure. Remove the rear chain from the gearcase sprocket. Lower the gearcase to the floor. Make sure not to damage the bolt. Lift the gearcase into position, angle the shaft which allows the installation of the rear drive chain.
Pull the shaft back into position. Remove the longer bolt, put the regular bolt back in position and tighten to ft. The end play must be between 0. If not the following parts may need replacing: Bearing, bearing cups, gear or gearcase housing. Install the dial indicator on the output shaft If not, the following parts may need replacing: Bearing, bearing cups, gear or gearcase housing.
The back lash must be between 0. If not, the following parts may need replacing: Large gear or the shaft. Measure the bore diameter for the seal. Correct diameter is 3. Install a dial indicator on the output shaft.
Set the indicator so the stylUS is against the pilot bore for the drive motor. Rotate the shaft degrees. Maximum run -out should not exceed 0. If either check Bore 1. Installation: Put "Boretite" sealant on the edge of the dust cap before installing it. Installation: Put Loctite on the bolt and tighten to ft. It is not necessary to remove the reduction gearcase to replace the seal at the input shaft, use the following procedure.
Install the new seal using the seal installation tool [Q]. Use a pry bar, pry the springs out of the operator cab II I Lift the operator cab with the chain hoist and remove it from the loader. Install a chain and chain hoist [QJ. Installation: Install the lower pivot pin first, use a screwdriver to hold the gas cylinder and install the top pivot pin.
Remove the nuts from the pivot bolts lID. Installation: Tighten the pivot bolts to ft. Installation: Install the lower pivot pin first.
Never open. To unfasten see directions in Service Manual to avoid loader damage or personal injury. Loosen the nut Item 1 B I Turn the bolt Item 2 in or out 00, until the door contacts both. Raise the lift arms, with the floor jack, until the pivot pin at the rod end of the lift cylinders can be removed.
Remove the pins at the rod end of the lift cylinders both sides '"'". Installation: Tighten the bolt at the pivot pin to ft. NOTE: The grease fitting at the pivot pin must be removed, because the grease can cause a lock and the pivot pin can not be removed form the Bob-Tach frame.
Hit the bolt to start the pivot pin into the Bob -Tach frame lID. Remove the bolt and use a punch to push the pivot pin into the Bob-Tach frame. Installation: Use a small diameter punch through the grease fitting hole to push the pivot pin into the lift arms.
After the Bob. Remove the block from the wedge bolt OOJ. I Assemble: Turn the block down until there is 6. Clean and inspect all the parts for wear and damage, replace the parts as needed. Buc;l, et Position Valve "" 0. Blue 16 16 39 40 Brown Black Brown 16 16 Back.. Blue 16 48 Right Flasher Lamp Opt. Blue 16 o Trans. Blue 16 16 e Enline Warn.
Charge Pressure 11 12 Lt. Green 16 White 12 8'. Starter 15 16 Lt. Thermo-Start or Glow Plug 20 Lt. BluelOranle cab. Green 18 18 e bRS. Charge Pressure Switch 14R Lt. BluelBlack 28B Lt. Blue 1. Blue Dk. CIte Rear Lamp tI Hourmeter. Fluid Temp..
Off 14R Lt.. Switch 28 Lt. BluelBlack 28B Lt.. Sender Lt. Blue 16 16 e Back-Up Ala. Blue 16 16 e Right Front Lamp 28 It.. Back-Up Alarm Switch Opt. Green 16 6 Trans. Charge Pressure 14RLt. BluelOrange 28S Lt. BluelYellow 16 8 e Fuel,Shut.. Fuel Sender. Blue 16 16 e.. Back-Up Alarm Opt. Wiper Opt. Blue 16 16 e Rleht Front Lamp 28 30 Lt.. Warning Light. Back-Up Alarm Swltchs Opt. Green 14R Lt..
GreenlWhite 16 16 8 Trans. I rrw IDS t. II JD If. Iii i"I ttilt. IOF few , ' lOS. W en 0 "-. Up Alarm Opt. Blue 42FR Ok. Blue 42R Ok. Blue Lt. Fluid Temp. Charge Pressure 14F Lt. Green 16 Switch 14R Lt. BluelBlack Lt. BluelOran,e 16 8 e Fa. The loader has a 12 volt, negative ground electrical system.
Instructions are necessary before operating or servicing There are two main circuits. Read Operator's Manual. Handbook and signs decals on machine. Follow warnings and instructions 1. The charging circuit has an alternator with built-in in the manuals when making repairs, adjustments or regulator , a voltmeter and a battery.
Failure to follow instructions can 2. The starting circuit has a starter motor, solenoids and other cause injury or death. The loader also has front and rear lights. Optional windshield wiper, horn and back-up alarm. The electrical system is protected by two fuses installed in the instrument panel.
Fuses protect the electrical system from an overload. Battery does not charge. Alternator will not charge. Starter will not turn the engine. Alternator belt is loose or damaged. Battery connections are dirty or loose. Battery is damaged. The ground connection is not making a good contact. The alternator is damaged. The engine is locked.
The starter is damaged. The wiring or the solenoid is damaged. Check the fuses. The Battery Manual has all the information and specifications needed for checking and servicing the battery.
Replace the battery as needed. Wear goggles and protective clothing and rubber gloves to keep acid off body. In case of acid contact, wash immediately with water o for several minutes and get medical attention. The battery has vent caps which will decrease the possibility of the battery being exploded by an external spark. Disconnect the battery cables. Always remove the negative - cable first to prevent sparks IAJ.
Remove the nuts and bolts from the holddown clamp and remove the holddown clamp rID. Connect a voltmeter between ground and No. If any of the tests show zero voltage, the wiring harness has a defect. Repair the wiring harness as needed. Connect the "BAT" wire to one side of the ammeter.
Disconnect the fuel shut-off wire at the injection pump. Turn the engine, with the starter for 30 seconds to lower the charge in the battery. Use the same procedure as above for "Checking Alternator Output" except for the following:.
Pulley 2. Bolts 3. Case Halves 4. If flammable debris is allowed to accumulate, it will increase the fire hazard. The loader must be cleaned as often as necessary to avoid this accumulation.
Flammable debris in the engine compartment is a fire hazard when the loader is parked with a hot engine. The spark arrestor muffler is designed to control the emission of hot particles from the engine and exhaust system, but the muffler and the exhaust gases are. Keep the battery terminals clean and tight. Repair or replace any damaged part. Tighten or replace any parts that show leakage. Always clean fluid spills.
Do not use gasoline or diesel fuel for cleaning parts. Use commercial nonflammable solvents. It has glow plugs. These starting aids can cause explosion and injure you or bystanders. Cover rubber hoses, battery and all other flammable parts.
Keep a fire extinguisher near the loader when welding. Have good ventilation when grinding or welding painted parts. Wear dust mask when grinding painted parts. Toxic dust or gas can be produced. No smoking! A fire extinguisher is available from your Bobcat dealer. The fire extinguisher can be installed in the location shown [A]. Early or later models identification made by serial number may use different parts, or it may be necessary to use a different procedure in doing a specific service operation.
The loader serial number plate is located on the inside of the left upright, above the grill [A]. Perkins TK 2. Isuzu 4JB1-PK01 The engine serial number is located on the fuel injection pump side and at the rear of the engine block [C]. Make sure it is filled out completely [D]. THE Bobcat loader is based-equipped with standard tires. The Bobcat loader is base-equipped with a standard operator cab as shown. The service schedule is a guide for correct maintenance of the Bobcat loader that must be done regularly.
Always use these service intervals unless very hot, cold, dusty or corrosive operating conditions make it necessary to increase the frequency of service. Failure to do so will cause damage to the loader or the engine. Instructions are necessary before operating or servicing machine. Read Operator's Manual, Handbook and signs decals on machine. Failure to follow instructions can cause injury or death. Engine Oil Check the oil level and add oil as needed.
Engine Air Cleaner Empty the dust cup. Replace the outer filter element only when the red ring shows in the indicator window. Check for leaks and damaged components. Engine Cooling System Clean debris from shrouds and grills. Check coolant level in the recovery tank and add as needed.
Tires Check for damaged tires and correct air pressure. Seat Belt and Seat Bar Check the condition of seat belt. Check the seat bar for correct operation. Safety Signs Decals Check for damaged signs Decals. Replace damaged signs Decals and signs Decals that are not in the correct location. Lift Arm and Bob. Operator Cab Check the fastening bolts, washers and nuts. Check the.
Wheel Nuts Check for loose wheel nuts. Tighten to correct torque if loose. Engine Oil and Filter Replace the oil and the engine oil filter. Battery Check the water level. Check battery cables for corrosion. Check that the battery cables are tight.
Check covers. Hydraulic Fluid, Tubelines Check the fluid level and add as needed. Check for damage and Hoses and leaks and replace as needed. Alternator Drive Belt Check the tension and adjust as needed. Chaincase Check the fluid level and add as needed. Controls and Brakes Check operation and adjust as needed. Spark Arrestor Muffler Remove the plug and clean the spark chamber. Seat Bar Grease pivot as needed. Steering Shaft Pivots Grease two 21 fittings.
Add oil to steering shaft. Hydraulic and Hydrostatic Replace filter elements. Filters U-Joint Grease three 31 fittings with correct grease. Reservoir Breather Cap Chaincase Replace the fluid. Hydraulic Fluid Reservoir Replace the hydraulic fluid. Read Operator's Manual. Handbook and signs decals on machine. A WARNING Put jackstands under the front axles and rear corners of frame before raising the operator cab, raising the lift arms or when the engine is running for service. Failure to use jackstands can allow the machine to fall or move and cause injury or death.
Put floor jack under the rear of the loader. Wood ramps may break and cause personal injury. One person must stay in the operator cab with the seat belt A WARNING fastened and the seat bar lowered, while the second person installs the stop over the rod of one lift cylinder I!
Eye and body protection is required when welding or grinding. Wear approved goggles, helmet and clothing. Failure to wear eye and body protection can result in Start the engine and raise the lift arms.
Changes to cab can cause loss of operator protection from rollover and falling objects, and result in injury or death. W C B The seat bar system has a pivoting seat bar with arm rests and has spring loaded latches for the lift and tilt control pedals. The operator controls the use of the seat bar. The seat bar in the down position keeps the operator in the seat and unlocks the foot pedals. When the seat bar is up, the lift and tilt pedals are locked in neutral position.
Operate each foot pedal to check both lift arm and tilt functions. Raise the lift arms until the bucket is about two feet mm off the ground. Raise the seat bar. Try to move each foot pedal. Pedals must be firmly locked in the neutral position.
There must be no motion of the lift arms or tilt bucket when the pedals are pushed. Stop the engine. Engage the parking brake. Raise the seat bar and operate the foot pedals to be sure that the pedals are firmly locked in the neutral position. Unfasten the seat belt. Inspect the linkage bolts and nuts. The correct torque is ft. I If seat bar system does not function correctly, check for free movement of each linkage part.
Check for excessive wear. Adjust pedal control linkages See Page for correct procedure. Replace parts that are worn, bent or broken. Service the system if pedals do not lock correctly. If the lift arms are up, a lift arm stop must be installed See Page Fender Bolt Stop the loader on a level surface. Stop the engine and engage the brake.
Put jackstands under the rear of the loader. Slowly raise the cab until it is all the way up [IDor lg. Stand on the safety tread A or beside the loader lgand slowly C lower the operator cab.
Failure to secure ROPS correctly can cause injury or death. If it is necessary to use an extra battery to start the engine. There must be one person in the operator's seat and one person to connect and disconnect the battery cables. Batteries contain acid which burns eyes and skin on The extra battery must be the same voltage as the loader contact. Wear goggles and protective clothing and battery.
In case of acid contact, wash immediately with water 1. Turn the key switch to the "OFF" position. When "jumping" from an extra battery make final connection negative at engine frame. Do not jump start or charge a frozen battery. Connect the second jumper cable to the negative -I Unplug charger before connecting or disconnecting terminal of the extra battery Item 31 and to the engine cables at battery.
Item 41 IA!. Battery gas can explode and cause serious injury. W 4. Keep the jumper cables away from moving parts. Immediately remove the negative - cable Item 41 from the engine IA! Battery cables are connected when using a fast charger or when welding on the loader Remove both cables from the battery. Extra battery cables booster cables are connected wrong. The remote start switch is required when the operator cab is in the raised position for service and the serviceman needs to start the engine.
A B E E Sheet 1 of 2 Printed in U. The fluid flows from the reservoir O to the inlet of the port block 8. Reservoir fluid is joined by the hydrostatic motor 8 case drain and the return fluid from the oil cooler e This combined flow. The hydraulic pump C, a "gear" type forces the fluid to the hydraulic control valve G.
When all three spools are in neutral position, the fluid goes through the control valve G and either to the reservoirO or to the port block 8. The hydraulic control valve G is a three section, parallel open center, closed port valve with a main relief valve 4D built into the inlet section of the control valve G. When one of the spools is activated, the fluid flow is directed to either the base end or the rod end of the cylinder s G 4D.
Return fluid from the other end of the cylinder s G 4D goes back to the hydraulic control valve G and goes to the 40 micron filter E in the port block G. The "tee" fitting at the outlet of the. Two sections on the control valve G can be used at the same time if the main relief valve e is not open. The by-pass valve e will open during cold weather or if there is excessive fluid pressure. The normal fluid flow through the 40 micron filter E , goes by the temperature switch 8 and against the neutral charge by-pass valve C,.
The normal flow is through the "tee" fitting between the temperature switch e and the charge by-pass valve e to the front O. The fluid flow is called "charge pressure" and supplies and the rear hydrostatic pumps the hydrostatic pumps O and the hydrostatic motors 8 with charge fluid.
The charge fluid is used by the pump and motor, but as the charge pressure increases, the charge by-pass valve e will open to prevent excessive pressure built up. The neutral charge fluid flows into each hydrostatic pump O and hydrostatic motor 8 to cool, lubricate and replenish the fluid supply which is lost through case drain.
Hydrostatic pumps O case drain flows into the inlet side of the hydraulic pump e through internal porting. There are two hydrostatic pumps O and two hydrostatic motors 8. One pump and one motor work together as a pair to drive on one side of the loader. The other pump and motor work as a pair to drive the opposite side of the loader.
The hydrostatic motors f also contain a shuttle valve to allow some of the fluid from the "drive loop" to go to the oil cooler 9 for cooling. Two for each side, one for forward travel and one for reverse travel. The high pressure replenishing valves 8 have a dual function.
In neutral the valve cartridges 8 are pushed off their seats to allow fluid flow from the charge loop to the cool, lubricate and replenish the pumps and the motors. When the swashplates are angled, the fluid is at a higher pressure than the charge fluid, this pressure difference causes the high pressure replenishing valves 8 to be forced against the seats. The high pressure replenishing valves 8 also act as a high pressure relief valve for the hydrostatic pumps e t in case of excessive pressure being generated by the hydrostatic pumps E.
The high pressure replenishing valves G will open allowing the "drive pressure" to relieve into the charge loop to be used again. Excess charge pressure fluid which is relieved over the charge by-pass valve E is routed to the "tee" and joins the hydrostatic motor f case drain fluid and flows to the oil cooler 9. The "tee" fitting has a pressure switch f that senses a drop in pressure of the fluid which goes to the oil cooler 9. Fluid from the oil cooler 9 flows through the filter O which has a built in by-pass valve G.
E E The fluid flows from the reservoir Oto the inlet of the port block G. Reservoir fluid is joined by the hydrostatic motor e case drain and the return fluid from the oil cooler 6 This combined flow supplies fluid to the hydraulic pump C,.
The hydraulic pump e a "gear" type forces the fluid to the hydraulic control valve G When all three spools are in neutral position, the fluid goes through the control valve G and either to the reservoir O or to the port block G. The hydraulic control valve G is a three section, parallel open center, closed port valve with a main relief valve CD built into the inlet section.
When one of the spools is activated, the fluid flow is directed to either the base end or the rod end of the cylinder s e Return fluid from the other end of the cylinder s e 48 goes back to the hydraulic control valve G and through the 3 micron filter E and back to the port block G.
The "tee" fitting at the outlet of the control valve G allows fluid to return to either the by-pass valve O and to the fluid reservoir 8 through a diffuser or through the 3 filter E and to the port block G during normal operation. Two sections on the control valve G can be used at the same time if the main relief valve CD is not open. The by-pass valve O will open during cold weather or if there is excessive fluid pressure.
The flow of fluid is through the 3 filter E , into the port block G , past the temperature switch 8 and against the neutral charge by-pass valve C. The normal flow is through the "tee" fitting between the temperature switch e and the charge by-pass valve e to the front and the rear hydrostatic pumps E.
This fluid flow is called "charge pressure" and supplies the hydrostatic pumps e and the hydrostatic motors e with charge fluid.
The charge fluid is used by the pump and motor, but as the charge pressure increases, the charge by-pass valve e will open to prevent excessive pressure build up. The neutral charge fluid flows into each hydrostatic pump E and hydrostatic motor f to cool, lubricate and replenish the fluid supply which is lost through case drain.
Case drain from the hydrostatic pumps e flows into the inlet side of the hydraulic pump e through internal porting. There are two hydrostatic pumps E and two hydrostatic motors f. One pump and one motor work together as a pair to drive one side of the loader. When the swashplates, of the hydrostatic pumps E , are angled in either direction, the hydrostatic pumps E force fluid, under high pressure, to the hydrostatic motors f.
The hydrostatic motors f. D for cooling. There are two for each side; one for forward travel and one for reverse travel. In neutral the valve cartridges O are pushed off their seats to allow fluid flow from the charge loop to the cool, lubricate and replenish the pumps and the motors. When the swashplates are angled, the fluid is at a higher pressure than the charge fluid, this pressure difference causes the high pressure replenishing valves G to be forced against the seats.
The high pressure replenishing valves G also act as a high pressure relief valve for the hydrostatic pumps O , in case of excessive pressure being generated by the hydrostatic pumps O. The high pressure replenishing valves O will open allowing the "drive pressure" to relieve into the charge loop to be used again. Excess charge pressure fluid which is relieved over the charge by-pass valve G is routed to the "tee" block and joins the hydrostatic motor 9 case drain fluid and flows to the oil cooler.
Fluid from the oil cooler f. Motor Case Drain 0. Charge Pump, Hydraulic Pump, The fluid reservoir O is filled by removing the breather cap G and filling fluid through the mesh screen e. Hydraulic fluid flows from the reservoir O and enters the inlet port of the tandem 2 sections gear pump 8. The larger section Ob of the tandem pump supplies pressure to the inlet of the hydraulic control valve G.
The pump pressure is controlled by the main relief valve O. The control valve 8 is a four-section, open center, closed port, series type valve. When all four spools are in neutral position, the fluid goes through the control valve and either to the hydraulic e or to the bucket position valve G. The lift section and tilt section of the control valve G work together to position the bucket as the lift arms of the loader are being raised.
The fluid from h E. The flow-control spool e has an orifice at each end. An increase in fluid pressure causes the check valve f to open which allows the flow of the fluid to the base end of the tilt cylinder 8.
The pressure relief G. The fluid flows through the oil cooler e , then through the hydrostatic filter and f1,. The fluid flows past the pressure switch E to the charge by-pass valve C,. The pressure switch E has a dual function, it starts the hourmeter and turns the warning light off.
Normal flow of fluid is through the four-way cross fitting to the front and rear hydrostatic pumps G. This fluid flow is called "charge pressure" and supplies the hydrostatic pumps G and the hydrostatic motors 8 with charge fluid. Case drain from the pumps G, flows into the inlet side of the hydraulic pump O through internal porting.
There are two hydrostatic pumps G and two hydrostatic motors O. The the swash plates of the hydrostatic pumps G, are angled in either direction, the pumps G, force fluid, under pressure, to the motorsO. The motors 8 turn and push the low pressure fluid back to the pumps G to be used again.
The motors 8 contain a shuttle valve which allows some fluid from the "drive loop" to go to the port block O and back to the reservoir O. There are two valves f for drive on each side of the loader: one for forward travel and one for reverse travel. In neutral the valve cartridges f are pushed off their seats to allow fluid flow from the charge loop to cool, lubricate and replenish the pumps and motors.
In forward or reverse when the swashplates are angled , the fluid has a higher pressure than charge fluid. This pressure difference forces one of the high pressure replenishing valves one per pump f against the seat. The high pressure replenishing valves f also act as a high pressure relief valve for the hydrostatic pumps G. The high pressure replenishing valves e will open allowing the "drive pressure" to relieve into the charge loop to be used again if excessive pressure is generated by the pumps G.
Excess charge pressure fluid which is relieved over the charge by-pass valve C, goes through the port block G and joins the hydrostatic motors O case drain fluid and flows to the reservoir O through the defusser 9.
Fluid from the cold oil by-pass valve 9 flows into the port block O and back to the reservoir O. Both the hydraulic filter e and the hydrostatic filter G have a by-pass valves. The diagnostic coupler e provides a quick access for checking the charge pressure. Hydraulic fluid flows from the reservoir O and enters the inlet port of the tandem 2 sections gear pump O. The larger section O b of the tandem pump supplies pressure to the inlet of the hydraulic control valve 8.
The pump pressure is controlled by the main relief valve 8. The lift section and tilt section of the control valve 8 work together to position the bucket as the lift arms of the loader are being raised. When the lift arms are being raised, the b hydraulic pump O flow is directed to the base end of the lift cylinders G. The fluid from the charge pump section 9a flows to either the oil cooler 9 or to the cooler by-pass valve 9. The cooler by-pass valve E will open when the fluid temperature is low cold or if there is excessive fluid pressure.
The fluid flows through the oil cooler 9 then through the hydrostatic filter G and into the four-way cross fitting.
The fluid flows past the pressure switch 8 to the charge by-pass valve 9. The pressure switch 8 has a dual function, it starts the hourmeter and turns the warning light off. Normal flow of fluid is through the four-way cross fitting to the front and rear hydrostatic pumps G , and also supplies fluid to actuate the steering servo controls G. This fluid flow is called charge pressure fluid. The charge fluid flows into each pump G, and motor 8 to cool, lubricate and replenish the fluid supply which is lost through case drain.
Case drain from the pumps G flows into the inlet side of the hydraulic pump O through internal porting. The return fluid from the steering servos G flows to the port block O. There are two hydrostatic pumps G and two hydrostatic motors 8. The swash plates of the hydrostatic pumps 9 are angled by the steering servo ,v. The motors O contain a shuttle valve which allows some fluid from the drive loop to go to the port block O and back to the reservoir O.
There are two valves G for drive on each side of the loader: one for forward travel and one for reverse travel. The valve cartridges G are pushed off their seats to allow fluid flow from the charge loop to cool, lubricate and replenish the pumps and motors. In forward or reverse when the swash plates are angled , the fluid has a higher pressure than charge fluid.
This pressure difference forces the high pressure replenishing valves G onto the seat. The high pressure replenishing valve G will open allowing the drive pressure to relieve into the charge loop to be used again if excessive pressure is generated by the pumps e. Fluid from the cold oil by-pass valve e flows into the port block O and back to the reservoir O under conditions of cold fluid or excess flow. The diagnostic coupler 9 provides a quick access for checking the charge pressure in the system.
The larger section f b of the tandem pump supplies pressure to the inlet of the hydraulic control valve G. The pump pressure is controlled by the main relief valve G.
The lift section and tilt section of the control valve G work together to position the bucket as the lift arms, of the loader, are being raised. When the lift arms are being raised, the b hydraulic pump O fluid flow is directed to the base end of the lift cylinders G,. The flow-control spool 9 and adjustable metering orificefJ split this flow.
The cooler by-pass valve f will open when the fluid temperature is low cold or if there is excessive fluid pressure. The fluid flows past the pressure switch 8 to the charge by-pass valve 8. Normal flow of fluid is through the four-way cross fitting to the front and rear hydrostatic pumps 9 , and also supplies fluid to actuate the steering servo controls e.
The charge fluid flows into each pump 9 and motor O to cool, lubricate and replenish the fluid supply which is lost through case drain. Case drain from the pumps 8 flows into the inlet side of the hydraulic pump 8 through internal porting. The return fluid from the steering servos e flows to the port block 8. There are two hydrostatic pumps 9 and two hydrostatic motors O. The swash plates of the hydrostatic pumps 9 are angled by the steering servo valves G in either direction, the pumps 9 force fluid, under pressure, to the motors 8.
The motors 8 turn and push the low pressure fluid back to the pumps 9 to be used again. There are two valves e for drive on each side of the loader: one for forward travel and one for reverse travel.
This pressure difference forces the high pressure replenishing valves 9 onto the seat. The high pressure replenishing valve e, will open allowing the drive pressure to relieve into the charge loop to be used again if excessive pressure is generated by the pumps fD.
Excess charge pressure fluid which is relieved over the charge by-pass valve 8 goes through the port block 8 and joins the hydrostatic motors O case drain and flows to the reservoir O through the diffuser 9. Fluid from the cold oil by-pass valve 8 flows into the port block 8 and back to the reservoir O under conditions of cold fluid or excess flow. The hydrostatic filter e has a by-pass valve e and a pressure differential switch e which indicates the condition of the filter element.
The diagnostic coupler G provides a quick access for checking the charge pressure in the system. Case drain hose was added from the hydrostatic pump G to the hydraulic reservoir 8 and the internal port between the hydraulic pump and hydrostatic pumps was removed on later production loaders.
Hydrostatic 3 Element b. Auxiliary Hydraulic Pump, 6. High Horsepower Control. Green 16 S4F Dk. Green 16 54G Dk. Green Lift and block the loader. Connect the hydraulic tester to the quick couplers 0 3. Disconnect the electrical connectors ea and eb. Start the engine. Check the main relief valve ED pressure. Access Plug 5. Engage the high flow hydraulics switch f. NOTE: If the pressure relief setting is adjusted, it will effect the standard relief pressure.
Always adjust the high pressure setting first. If adjustment is needed, loosen the jam nut and adjust the high flow relief valve pressure by turning in to increase pressure or out to decrease pressure. Screw Adjustment 7. Disengage the high flow hydraulics. Remove the access plug or loosen the jam nut on the main relief valve.
ED To check the relief valve in the hydraulic d pump f end section: connect the hydraulic 9. Use an allen wrench and turn c tester into the outlet line of the pump e. By the screw in to increase pressure or out to restricting the flow, with the hydraulic tester, the decrease pressure. Install the access plug or tighten the jam nut. Disconnect the hydraulic tester. VALVE b. Green 16 S4EA Dk. Green 16 I!
Connect the hydraulic tester to the quick couplers Q. All tests are done with engine speed at full RPM. Check main relief valve pressure. T he correct pressure for the low setting is PSI kPa. NOTE: If adjustment is necessary , adjust 6. When the low pressure setting is correct, the low pressure setting before adjusting the high pressure setting.
To adjust the low pressure on the main relief valve the following procedure: e' use a. Remove the high pressure adjustment stop Item 3! Turn the adjusting guide Item 4 in c. One turn is equal to d. Install the high pressure adjustment e. Connect the pilot horsepower" function and check for hose. Start the engine and check the the correct pressure. Repeat the i proceddure until the pressure setting!
Repeat the is correct. Hydraulic fluid flows from the reservoir Oand enters the inlet port of the triple 3 section gear pump G G. The larger section a of the pump supplies fiow to the inlet of the hydraulic control valve EB O.
The pump pressure is controlled by the main relief valve. The control EB e valve is a four-section, open center, closed port, series type valve. Wilen all four spools are in neutral position, the fluid goes through the control valve and to the hydraulic filterG.
When the lift arms are raised, the hydraulic pump G a fluid flow is directed to the base end of the lift cylinders G. The fluid from the rod end of the lift cylinders e returns to the bucket position valveG and is directed to the center of the flow-control spool e.
The flow-control spool f and flow adjustment valve G direct this flow. A percentage of the fluid is directed over the flow adjustment valve G to position the bucket. The rest of the e e fluid is directed through the orifice in the flow-control spool and onto the return port of the control valve lift section.
The fluid from the charge pump b flows to the four-way cross fitting and is called "charge pressure fluid". The fluid flows to the oil cooler G or oil cooler by-pass valve The oil cooler by-pass valve 9 will open when the fluid temperature is cold or if there is excessive G , then through the hydrostatic e fluid pressure. The charge pressure fluid flows into each pump 8 and motor G to cool, lubricate and replenish the fluid supply which has been lost through case drain. Also fluid from the four-way cross fitting supplies fluid to actuate the steering servo controls ED and the electrical solenoids fl for high horsepower operation.
The return fluid from the steering servo controls EDand electrical solenoids fl flows to the port block 8. There are two hydrostatic pumps 8 and two hydrostatic motors G. The swash plates of the hydrostatic pumps 8 are angled by the steering servo 9 8 force fluid, under pressure, to the motors G. The motors G contain a shuttle valve which allows some fluid from the drive loop to go to the port block 8and back to the reservoir O. There are two valves for drive on each side of the loader: one for forward travel and one for reverse travel.
This pressure difference forces the high pressure replenishing valve CD onto the seat. The high pressure replenishing valve CD will open allowing the drive pressure to relieve into the charge loop to be used again- if excessive pressure is generated by the pumps 8.
Excess charge pressure fluid which is relieved over the charge by-pass valve E goes through the port block 8 and joins the hydrostatic motors G case drain and flows to the reservoir through the diffuser O O. Fluid from the cold oil by-pass valve flows into the port block 8 and back to the reservoir O under conditions of cold fluid or excess flow.
The hydraulic filter G has a by-pass valve G to protect the system if the filter element becomes plugged. The hydrostatic filter G has a by-pass valve G to protect the system if the filter element becomes plugged and a pressure differential switch CD which indicates the condition of the filter element.
Turning the switch II] "ON" for high flow operation will activate the following functions: it will energize the electrical solenoid fJ a, and the electrical selector valve G. This fluid than flows to the high flow quick coupler E at the front of the loader.
The return fluid flows to the control valve 9 and to the hydraulic filterG. Case drain fluid Example: Planer will return through the coupler 49 and back to the port block 8 to join the fluid going to the reservoir O.
When the high flow operation is engaged; it will engage the pilot operated main relief valve f which will increase the relief pressure to PSI kPa. The return fluid goes to the control valve 9 and to the hydraulic filterG G. The electrical selector valve is not energized in this function. MC Forward Fluid Flow sov Black 16 b. Reverse Fluid Flow sow 16 54[ Black Dk.
Green 16 54EB Lt. Check the main relief valve pressure. Engage the high flow hydraulic system 28 t Jam Nut Access Plug. NOTE: If the high pressure relief setting is adjusted, it will effect the standard relief pressure. If adjustment is needed, loosen the jam Adjustment nut and adjust the high flow relief valve High Pressure Screw pressure by turning in to increase Adjustment pressure or out to decrease pressure. Install the access plug 7. Stop or tighten the jam nut.
Disconnect the the engine. Tighten the jam nut to 35 ft. To check the relief valve G in the. Remove the access plug or loosen the hydraulic pump end section: connect the jam nut on the main relief valve hydraulic tester into the outlet of the pump.
By restricting the flow, with 9. Use an allen wrench and the hydraulic tester, the pressure should turn the screw in to increase or out to be PSI kPa at the relief decrease pressure.
The correct setting is valve G. Hydraulic fluid flows from the reservoir O and enters the inlet port of the triple 3 section G G. The larger section a of the pump supplies flow to the inlet of the hydraulic e. The control e control valve valve is a four-section, open center, closed port, series type valve. When the lift arms are raised, the hydraulic pump G a fluid flow is directed to the base end of the lift cylinders f. The flow-control spool 9and flow adjustment valve Gdirect this flow.
The fluid from the charge pump b flows to the four-way cross fitting and is called "charge G e pressure fluid". The fluid flows to the oil cooler or oil cooler by-pass valve The oil cooler by-pass valve will open when the fluid temperature is cold or if there is excessive fluid pressure.
The fluid flows through the oil cooler G , then through the hydrostatic filter8 and past the pressure switch f to supply the front and rear hydrostatic pump Q with charge pressure and on to the charge by-pass valve E. The pressure switch f has a dual function, it starts the hourmeter and turns the warning light off.
Also fluid from the four-way cross fitting supplies fluid to actuate the steering servo controls f and the electrical solenoids O for high horsepower operation. The return fluid from the steering servo controls G, and electrical solenoids O flows to the port block G. The swash plates of the hydrostatic pumps 8 are angled by the steering servo controls 9 in either direction, the pumps 8 force fluid, under pressure, to the motors G.
The motors G turn and p. The motors G contain a shuttle valve which allows some fluid from the drive loop to go to the port block 8 and back to the reservoir O. In forward or reverse when the swash plates are angled , the fluid has a higher pressure the charge fluid.
This pressure difference forces the high pressure replenishing valve 0, onto the seat. Fluid from the cold oil by-pass valve 0 flows into the port block G and back to the reservoir O under conditions of cold fluid or excess flow. The hydraulic filter G has a by-pass valve ED to protect the system if the filter element becomes plugged.
The hydrostatic filter G has a by-pass valve f to protect the system if the filter element becomes plugged and a pressure differential switch CD which indicates the condition of the filter element. Turning the switch fl "ON" for high flow operation will activate the following functions: it will energize the electrical solenoid9 e a, the main relief valve and the electrical selector valve El. When the electrical solenoid 9 e a is energized the charge pressure will shift the.
This fluid than flows to the high flow quick coupler CB at the front of the loader. The return fluid flows to the control valve f and to the hydraulic filter f;. Case drain fluid Example: P laner will return through the coupler G and back to the port block G to join the fluid going to the reservoir O. When the high flow operation is engaged; it also energized the main relief valve e which. Gf e The fluid from the auxiliary hydraulic pump c when not in use, flows to the electrical selector valve and returns to the hydraulic tilter G.
Turning the switch fl "REV" for reverse operation will active the electrical solenoid eb and shift the control valve spool 9to allow fluid flow from the hydraulic pump a to a, 8.
The return fluid goes to the control valve f and to the e flow to the high flow coupler hydraulic filterG. C harge Pump, Hydraulic fluid flows from the reservoir f to the infet port of the tandem 2 section gear pump 8. The larger section 4D b of the hydraulic pump suppiies pressure to the inlet of the hydraulic control valve G. The pump pressure is controlled by the main relief valve C's. When all three spools are in neutral position, the fluid goes through the control valve e to the hydraulic filter 9.
As the fluid goes into one end of the cylinder s G 4D the fluid from the other side of the cylinder flows back into the control valve G. When the cylinder s G e reach the end of the stroke, the fluid reaches the setting of the main relief valve C's , it will open and let the fluid by-pass the-hydraulic circuit internally and go back to the reservoir e.
The fluid flows from the charge pump 9a to either the oil cooler 9 or the cooler by-pass valve 8 which will open when there is cold fluid or if there is excessive fluid pressure. The fluid flows past the pressure switch G to the charge by-pass valve E. The pressure switch G has a dual function, it starts the hourmeter and turns the warning light "OFF".
Normal flow of fluid is through the four-way block to the front and rear hydrostatic pumps G. This fluid flow is called "charge pressure" and supplies the hydrostatic pumps G and hydrostatic motors G with charge fluid. The charge fluid is used by the pumps and motors, but as the charge pressure increases, the charge by-pass valve G will open to prevent excessive pressure build-up. The charge fluid flows into each pump G and motor G to cool, lubricate and replenish the fluid supply which is lost through case drain.
Case drain from the pumps G flows into the inlet side of the hydraulic pump e through internal porting. There are two hydrostatic pumps G and motors G. The swashplates of the hydrostatic pumps G are angled to either direction, the pumps G force fluid, under pressure, to the motors G. The motors G turn and push the low pressure fluid back to the pumps 9 to be used again.
The motors G contain a shuttle valve which allows some fluid from the "drive loop" to go to the port block 8 and back to the reservoir e. There are two valves G for drive on each side of the loader. In neutral the valve cartridges G are pushed off their seats to allow fluid flow from the charge loop to cool, lubricate and replenish the pumps e and motors G.
In forward or reverse travel, the fluid has a higher pressure than charge pressure fluid. This pressure difference forces one of the high pressure replenishing valves G against the seat.
The high pressure replenishing valves G also act as a high pressure relief valve for the pumps G. The high pressure replenishing valves G will open allowing the "drive pressure" to relieve into the charge loop to be used again if excessive pressure is generated by the pumps G. Excess charge pressure fluid which is relieved over the charge by-pass valve O goes through the port block 8 and joins the hydrostatic motors G case drain fluid and flows to the reservoir f through the defuser 8.
The hydrostatic filter 9 also has a pressure differential switch ED which indicates the condition of the filter. The diagnostic coupler G provides a quick access for checking the charge pressure. The lift and tilt section of the control valve G work together to position the bucket as the lift arms are being raised. The flow-control spool f! Some of the fluid flow is directed to the base end of the tilt cylinder G and the other portion of the fluid is directed through the opposite end of the flow-control spool e to the return port of the lift section of the control valve G.
The fluid flow from the flow-control spool e is against the Un-loading spool e and flow adjustment valve 9.
An increase in fluid pressure causes the flow adjustment valve 9 to open which allows the flow of the fluid to the base end of the tilt cylinder G. The following troubleshooting chart is provided as an assistance in locating and correcting problems which are most common. Many of the recommended procedures must be done by authorized Bobcat Service Personnel only. The hydraulic system will not operate. Slow hydraulic system action. Hydraulic action is not smooth.
Lift arms go up slowly at full engine RPM. The bucket does not self-level. The bucket will partially self-level. The fluid level is not correct. The pedal linkage is disconnected. The hydraulic pump has a defect. The relief valve has a defect. The pedal linkage is not adjusted correctly. Relief valve is not at the correct pressure.
Suction leak on the inlet side of the hydraulic pump. Fluid is cold. Using the loader for more than its rated capacity. Spool in the valve section is not centering or the centering spring is broken. Internal leak at the lift cylinder s. External leak at the lift cylinder s. Port relief seal is leaking. Load check has a defect in the valve section. Check the flow divider. Check the unloading spool. Check the self-level relief. Tighten to Correct Clean outside of all assemblies before beginning repairs.
Amount from Chart Use plugs and caps to cover open ports. Dirt can quickly damage the system. Tube Size Rotate No. Use the following procedure to tighten the flare fitting: Wrench Size Outside Dia. Thread Size of Hex Flats Tighten the nut until it makes contact with the seat. When installing this fitting, the 0-ring must be first lubricated.
Loosen the jam nut, install the fitting into place, then tighten the jam nut. Tighten the jam nut until it and the washer are tight against the surface [g. Make replacement of tubelines which are bent or have become flat. There will be a restriction of fluid flow, which will give a slow hydraulic action and cause heat. A Make replacement of hoses which show signs of wear, damage or weather cracked rubber. When installing tubelines or hoses, make sure you use two wrenches when loosening and tighten them.
Lower the lift arms. Activate the lift pedal to release the hydraulic pressure. Only check one cylinder at a time. Fluid leaks under pressure may not be visible. Use a piece of cardboard or wood to find leaks. Do not use your bare hand. Wear safety goggles. If fluid enters skin or eyes, get immediate medical attention. Start the engine and push the top toe of the lift pedal. If there is any leakage from the open hose, remove the cylinder for repair.
Raise the lift arms. Install jackstands under the Bob. Installation: Tighten the lock bolt to ft. Slide the cylinder forward a small amount. Disconnect the hoses from the cylinder! Remove the bucket. Roll the Bob-Tach fully backward. Activate the tilt pedal to release the hydraulic pressure.
Put a plug in the hose. Do not use your bare I hand. Start the engine and push the bottom heel of the tilt pedal. Remove the bucket or attachment. Roll the Bob. Push the tilt pedal to release the hydraulic pressure. Remove the old seal at the rod end of the cylinder. NOTE: If there is movement between the head and the snap ring the complete cylinder must be replaced.
B Put the base end of the cylinder in a drain pan. Move the rod in and out to remove the fluid from the cylinder barrel. Put a wrench on the fitting and turn the end cap counterclockwise to remove the retainer ring [ID. B B NOT E: To prevent damage to the teflon seal, do not turn it into the piston groove. Install the piston into the. Install the piston into the cylinder barrel and work the teflon seal and 0-ring past the slot in the barrel [ID. Push the cylinder rod in and out the full length.
It must travel freely through the full stroke. Put the base end of the cylinder in a drain pan. Put the base end of the cylinder in a vise. Wash all the parts in clean solvent. Dry with air only. Destroy all the old seals and 0-rings. NOTE: To prevent damage to the teflon seal, do not turn it into the piston groove.
Install the piston into the tapered end of the tool to get the teflon seal to the piston size diameter. NOTE: On tilt cylinder with tapered sleeve, install the sleeve with the taper toward the eye end of the rod. NOTE: On tilt cylinder with tapered piston, install the piston with the taper toward the eye end of the rod.
Tilt Cylinder Tapered Sleeve - ft.
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