COVER GP-CONTROL VALVE 2710877 - Caterpillar

Service Brake Disc Check
Make reference to on first page of Air System And Brakes Testing And Adjusting section.
Service Brake Disc
(1) Disc. (2) Separator. (3) Piston. (A) Thickness of disc.The front and rear axles each have two threaded plugs that are used to inspect the corresponding left and right brake discs. The inspection plugs are located on the front of the front axle and on the rear of the rear axle. The procedure to check the brake discs for wear is the same for the front and rear brakes.
This check requires an operator and a mechanic. Make reference to on first page of Testing And Adjusting section.
1. With the engine off and the parking brake engaged, remove the inspection plug which corresponds to the brake disc to be checked.2. Depress and hold either brake pedal. This will hold piston (3), disc (1), and separator (2) tight against one another.3. Using a feeler gauge, measure thickness of disc (A).4. The minimum thickness of disc (A) worn is 7.92 mm (.312 in). The thickness of disc (A) new is approximately 9.1 mm (.358 in). Service the brake before the thickness of disc (A) is less the 7.92 mm (.312 in).Accumulator Charging Valve
0 to 20 700 kPa (0 to 3000 psi)pressure gauge.
Personal injury or death can result if two persons are not used in the following procedures.Make reference to the S on the first page of the Testing And Adjusting section.
There are two separate procedures that may be used to check the operation of the accumulator charging valve and several associated components.Procedure 1 is a quick method to check for correct cut-out pressure, and indicate whether or not the low brake oil pressure switch and alert indicator are working correctly. It will also provide an estimate of the accumulator pre-charge level, and indicate approximately how many brake applications an operator may have before the low brake oil pressure alert indicator turns on (providing the service brake system is operating correctly).Procedure 2 determines if the cut-in and cut-out pressures for the accumulator charging valve are correct. It also provides the steps required to adjust the accumulator charging valve.Procedure 1
1. Stop the engine and completely remove all oil pressure from the brake circuit by this method: Engage the parking brake. Repeatedly push on the brake pedal until there is no brake pressure.
Accumulator Charging Valve Pressure Tap Location
(1) Accumulator charging valve. (2) Accumulator charging pressure tap. (Accumulator charging valve can be accessed from panel directly behind operator compartment. Shown from left side of machine with left side access panel removed for clarity.)2. Install a 0 to 20 700 kPa (0 to 3000 psi) pressure gauge to pressure tap (2) on the accumulator charging valve.3. Look at the pressure gauge. Before the engine is started, the oil pressure must be 0 kPa (0 psi).4. Start the engine. Allow the oil pressure to increase to the cut-out pressure. The correct cut-out pressure is 14 485 345 kPa (2100 50 psi).5. After the service brake accumulators