LEG-PULLER 6V7888 - Caterpillar

Personal injury or death can result from machine movement.Place blocks in front of and behind the wheels to make sure the machine does not move while the parking brakes are disengaged.
Personal injury or death can result from air in the oil for the brake hydraulic system.Air in the system can prevent complete brake application and it is possible that the wheels on the machine can not be stopped.Air must not be in the oil for the brake hydraulic system to function properly.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Table 1
Tools Needed     Qty    
8T-0857 Pressure Gauge (
0 to 10000 kPa (0 to 1450 psi))     1    
6V-9830 Cap Assembly     1    
6V-9509 Face Seal Plug     1    An internal oil leak in the brake release system will cause too much friction between the brake discs and the plates, which can damage these components when the machine is moving.Note: It may be necessary to troubleshoot for leakage in the traction control valve.
Remove the air from the brake release system. Perform the procedure for the Parking Brake in the Testing and Adjusting, "Brake System Air - Purge".
Use a coupler and a hose to connect a 8T-0857 Pressure Gauge (0 to 10000 kPa (0 to 1450 psi)) at pressure tap (1) and at pressure tap (2) .
Start the engine. Operate the engine at low idle.
Move the lever for the parking brake control to the OFF position.
Operate the engine until the pressure stops increasing. Then, stop the engine.
Record the pressure decrease in the first minute in Table 2.
Table 2
Decrease In Pressure In The First Minute    
Plugged Wheel     Pressure Decrease    
No plugged wheels        
Left Rear        
Right Rear        
Left Front        
Right Front        
Apply the parking brake.
Illustration 1 g00598004
Front wheel (3) Oil line for the application of the parking and secondary brake release
Illustration 2 g00598123
Rear wheel (3) Oil line for the application of the parking and secondary brake release
Remove oil line (3) that is for the release of the parking brakes at one of the wheels.
Cap oil line (3) with a 6V-9830 Cap Assembly. Plug the fitting on the wheel with a 6V-9509 Face Seal Plug .
Start the engine. Operate the engine at low idle.
Move the parking brake control to the OFF position.
Operate the engine until the pressure stops increasing. Then, stop the engine.
Record the pressure decrease in the first minute in Table 2.
Apply the parking brake.
Repeat Step 8 through Step 14 for each wheel.Note: Compare the data in Table 2 in order to determine the