VALVE GP-MAIN CONTROL 2982877 - Caterpillar

Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.To prevent possible injury, perform the procedure that follows before testing and adjusting the brake system.
Specification
Table 1
Brake Accumulator Charging Valve - Test
Date Equipment ID Code
Description Specification Actual
Cut-in Pressure 15000 350 kPa (2175 50 psi)
Cut-out Pressure 18000 350 kPa (2610 50 psi) Introduction
This test will check the performance of the accumulator charging valve and accumulators.Required Tooling
Illustration 1 g01623868
Tooling (B)
Table 2
Tool Item Part Number Description Qty
B 198-4240 Digital Pressure Indicator Gp
B1 198-4234 Digital Indicator 1
B2 251-9600 Pressure Sensor Gp (0 to 68,900 kPa (0 to 10,000 psi)) 2
B3 198-4236 Adapter Cable As 2 Preparation for Test
Warm the hydraulic oil up to 65° 5°C (149° 9°F).
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel. Warm up the engine to the normal operating temperature. Place the transmission direction control switch in the NEUTRAL position. Engage the parking brake. Lower the bowl to the ground and lower the apron onto the bowl. Stop the engine and put chocks in front of the wheels and behind the wheels.
Illustration 2 g03715825
Looking up at the tractor with the belly pan removed
Remove the crank case guards to allow access to the control manifold for the hydraulic fan and brake. For information regarding the removal of the crankcase guards refer to the Disassembly and Assembly, "Crankcase Guard - Remove and Install - Tractor" for your machine.
Pump the brakes to remove the pressure from the system.
Illustration 3 g06218162
View of the control manifold for the hydraulic fan and brake as seen from the front of the tractor.
Illustration 4 g06218164
(1) Test port as seen in a close up view of the control manifold for the fan and brake. Viewed from beneath the tractor.
Connect (B) to test port (1).Perform the Test
Start the engine. Run the engine at low idle and place the parking brake switch in the OFF position.
Pump the brake pedal until the cut-in pressure of 15000 350 kPa (2175 50 psi) is reached. Allow the accumulators to reach the cut-out pressure of 18000 350 kPa (2610 50 psi).
Immediately shut off the engine and immediately cycle the key back to the ON position. Parking brake indicator (3) will illuminate
Illustration 5 g03491397
Illustration 6 g03491437
Your machine will have one of the above monitoring system displays.
Pump the service brakes at a rate of one second on and one second off. Count the number of brake applications that are required to illuminate the low-pressure warning indicator (2).
Turn the engine key to the start position and operate the engine at low idle and allow the brake accumulators to reach the cut-out pressure. Run the engine at low idle, the machine in park, and the service brakes released.Note: The accumulator pressure should not decrease from the cut-out pressure to the cut-in pressure in less than 30 seconds.
Remove the test equipment (B)