INJECTOR GP- 1601695 - Caterpillar

To prevent possible injury, make sure all of the air pressure is released from the air tank before you disconnect the test gauges and the hose assemblies.
A change in the braking characteristics or a low pressure warning may be an indication of a failure in one of the brake circuits. Personal injury or death may occur if the machine is operated before repairs have been made or before all circuits have been checked. Always check the brakes after brake repairs have been made and before the machine is put back into use.
Introduction
This procedure will check the service brake control valve.Required Tools
Illustration 1 g01623868
Table 1
Tool    Item    Part Number    Description    Qty    
B     198-4240     Digital Pressure Indicator Gp        
    B1     198-4234     Digital Indicator     1    
B2 198-4239     Pressure Sensor Gp (0 to 41,369 kPa (0 to 6,000 psi))     2    
B3 198-4236     Adapter Cable As     2    
F     6V-3966     Fitting As     2    
G     3B-7722     Pipe Bushing     2    
H     7J-8611     Pipe Elbow     2    Machine preparation
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel and lower all implements to the ground. Place the transmission direction control lever in the NEUTRAL position. Stop the engine and put chocks in front of the wheels and behind the wheels.
Illustration 2 g01721275
(1) Air tank (2) Drain valve
Open the drain valves (2) on the air tank. Depress the brake pedal several times until there is no resistance. This process will relieve the air pressure in the system.
Illustration 3 g01721293
View of Tandem Housing (3) Junction block
Remove the plugs from the top of junction blocks (3) on each tandem housing.
Assemble tooling (G) , tooling (H) , and tooling (F) together and connect the assembly to the open ports in junction blocks (3) on each tandem housing.
Attach tooling (B) to tooling (F) .
Close the drain valves on the air tank.Test Procedure
Start the engine. Allow the air pressure to increase to the cut out pressure. The cut out pressure should be 1000 34 kPa (145 5 psi).
Apply the service brake control (pedal) and release the service brake control (pedal) several times. Check the air pressure at the tandem housings in order to verify that the air pressure changes.Note: The air pressure should be the same amount for both the left service brakes and the right service brakes when the pedal is moved.
Apply the service brakes fully.
Release the service brakes. Immediately after releasing the service brakes, the reading on the test pressure gauges should read 0 kPa (0 psi). If the reading does not read 0 kPa (0 psi) immediately after releasing the brakes, refer to Troubleshooting, "Air System and Brakes".
Stop the engine.
Open the drain valves (2) on the air tank. Depress the brake pedal several times until there is no resistance. This process will relieve