PUMP GP-SUMP 7N7069 - Caterpillar

Exhaust the air from the tractor reservoirs by opening the drain valve. Remove the valve from the front tank and install the air hose and gauge. Start the diesel engine and allow the air pressure to build up to cut-out pressure. Compare the readings of the dash-mounted air pressure gauge with that of the test gauge. If the gauge readings at cut-out pressure differ by more than 5 psi (0.35 kg/cm2), install a new gauge. Leave the test gauge connected for further tests.
INSTRUMENTS
1. Emergency air brake control valve. 2. Air pressure gauge. 3. Air horn valve.Tractor Air Compressor Governor
The correct air compressor governor cut-out pressure is 122 4 psi (8.6 0.3 kg/cm2). To adjust the cut-out pressure, remove the governor cap and loosen the locknut. Turn the adjusting screw to achieve the correct cut-out pressure [one turn causes a 20 psi (1.4 kg/cm2) pressure change].
TRACTOR AIR COMPRESSOR GOVERNOR
1. Adjusting screw. 2. Locknut.Pressure Protection Valve
PRESSURE PROTECTION VALVE
1. Pressure protection valve. 2. Junction block.The pressure protection valve is located beneath the floor plate and near the steering control valve. To test the valve, relieve all air pressure from the reservoirs and the accessory circuits and then begin air pressure buildup. As the pressure is being built up, hold the horn button depressed and note the pressure reading on the test gauge. When the horn begins to sound, the valve has opened and admitted air to the accessory air circuit. The horn should sound at 75 psi (5.3 kg/cm2). The opening pressure of the valve is adjusted by turning the cap on the end of the valve. Turning the cap clockwise raises the opening pressure.Pilot Valve
The pilot valve is located beneath the tractor floor plates. It may be located by tracing the line from the differential lock valve to the pilot valve control port.Operation of the pilot valve may be tested by depressing the differential lock pedal and trying to apply the selector brakes. If the selector brake can be applied with the differential lock valve depressed, the pilot valve is not functioning and should be replaced.Emergency Brake Control Valve
Start the tractor diesel engine and allow the air system to build up to cut-out pressure. Stop the engine and push the emergency brake control valve knob IN. Relieve the air pressure in the reservoir by repeatedly applying the service brakes and note the pressure reading on the test gauge at which the valve pops out and the emergency brakes apply. The valve should pop out when the air reservoir pressure reaches 40 5 psi (2.8 0.4 kg/cm2). If not, install new valve.
INSTRUMENTS
1. Air pressure gauge. 2. Emergency brake control valve.Inversion Valve
The operational test of the inversion valve is dependent upon correct operation of the emergency brake control valve.The operation of the dash-mounted inversion valve (1) may be checked by noting the reservoir pressure at which the valve releases and applies the emergency brakes. With the tractor engine running, relieve the pressure slowly and steadily at the reservoir