ELECTRONICS GP-ENGINE RATINGS 2151491 - Caterpillar

Illustration 4 g00284783
Front slack adjuster
(3) Fitting
(4) HoseNote: Make sure that the air pressure is removed from the system before you continue with this procedure.
To check for leakage of the master cylinder, disconnect hose (4) from the slack adjuster and install a plug into fitting (3).Use a 6V-9509 Face Seal Plug with the front brake system.Use a 6V-9511 Face Seal Plug for the rear brake system.
Install the FT1097 Displacement Gauge. Start the engine and allow the air system pressure to rise above 550 kPa (80 psi).
Activate the service brakes or the retarder. Push down the rod of the displacement gauge until the rod contacts the plate in the master cylinder. Measure the extension of the rod.
After approximately 10 minutes, push down on the rod again. Measure the distance. A decrease in the extension length of more than 3.2 mm (.125 inch) during the 10 minute check is an indication of leakage.
If no leakage is indicated, see "Brake Piston Seal Leakage Check".
If no leakage is indicated, check all hose connections for leaks. Also, check the outside of the master cylinder for leaks. If no external leaks are found, check the master cylinder piston seals and the makeup valve for wear or for damage.Brake Piston Seal Leakage Check
Table 3
Required Tools
Item Part Number Description Qty
1 FT1097 Displacement Gauge 2
2 9D-3352 Elbow 2
3 6V-9830 Cap As 1
4 6V-9831 Cap As 1
Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine.To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.
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.
Illustration 5 g06023008
Location of elbow on front brake master cylinder
(A) Hose
(B) Elbow
Illustration 6 g06023012
Location of elbow on rear brake master cylinder
(C) Hose
(D) Elbow
Remove the air pressure from the system before performing this procedure.
Disconnect hose (A) from elbow (B) on the front brake master cylinder.
Remove elbow (B) from the top of the front brake master cylinder.
Install elbow (2) into the top of front brake master cylinder.
Connect hose (A) to elbow (2) and install displacement gauge (1) to the top of elbow (2).
Disconnect hose (C) from elbow (D) on the rear brake master cylinder.
Remove elbow (D) from the top of the rear brake master cylinder.
Install elbow (2) into the top of rear brake master cylinder.
Connect hose (C) to elbow (2) and install displacement gauge (1) to the top of elbow (2).
Do not exceed the air pressure of 830 35 kPa (120 5 psi) or damage can occur to the air system components.
Use an external air supply to charge the air system.
Start the engine. Allow the air pressure to reach the cutout pressure. Keep the engine in operation during this