PISTON AS 2159979 - Caterpillar

When the axle shafts are removed, the machine has NO parking brakes. The machine can roll and cause personal injury or death.Block the tracks securely so that the machine cannot move.The towing connection must be rigid, or towing must be done by two machines of the same size or larger than the towed machine. Connect a machine on each end of towed machine.Be sure all necessary repairs and adjustments have been made before a machine that has been towed to a service area, is put back into operation.
Verify that all instructions that are outlined in the Operation and Maintenance Manual, "Towing Information" section are carefully followed.Engine Stopped
You can move the machine when the engine is not operable. You must use a brake release pump.Consult your Caterpillar dealer for the equipment that is necessary for towing a disabled machine.The pressure hose from the brake release pump connects to the brake valve. The pump takes oil from the sump of the brake release pump. Then, the pump pressurizes the brake valve in order to release the brake.Note: This machine is free to move. This machine is free to roll away and this machine has no braking ability when both brakes have been released.Connection of Brake Release Pump
Illustration 1 g00277928
The machine brakes can be released for towing. Use the following tools:
FT1845 Pump (1)
FT1973 Adapter (not shown) Pump Test
Possible brake piston seal damage could result without checking relief valve. Opening pressure must be checked and adjusted before connection is made.
Install plug (5) in the pressure hose.
Turn the handle of bypass valve (4) to the closed position.
While you are pumping handle (3), observe the pressure when relief valve (2) opens.
Adjust the opening pressure of the relief valve. Set the pressure to 3030 70 kPa (440.0 10.0 psi).Towing Plugs
Open the engine access doors that are located on the left side of the machine.
Locate the main charge and the relief valve housing on the hydrostatic transmission.
Illustration 2 g00688927
Remove the plug from the inside of the valve housing. Install an exterior plug into this position. The removal of this valve allows the motor to turn.Connection For The Pump
Illustration 3 g00518316
Disconnect the hose from the right side of the brake manifold.
Install an 8M-0505 Connector to the port in the brake manifold. Connect the remainder of the FT1973 Adapter to the pump pressure hose.
Route the pressure hose through the door opening of the operator's compartment to the pump.
Place the pump in front of the operator.
Move the transmission lock lever to the UNLOCKED position.
Fasten the seat belt. Continue to the next topic.Brake Release
Illustration 4 g00277932
Turn bypass valve handle (4) to the CLOSED position.
Initially, rapidly move the pump handle. This will produce a large volume of oil flow.
The brake piston seal must be fully seated. A sudden rise in the oil pressure will verify that the seal has seated properly.
When the seal is properly seated, the pressure rises to the maximum.
Now, the machine can be towed.
Do not allow pressure to drop below 2756 kPa (400 psi) while towing.Partial brake engagement could