SHIELD- 4718926 - Caterpillar

DRAIN VALVES
1-Front tank drain valve. 2-Rear tank drain valve.Exhaust the air from the tractor reservoirs by opening the rear drain valve. Because of one way check valves, this is the only way to drain both reservoirs through one drain.Remove the valve from the rear 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.Air Compressor Governor
Start the engine and allow the air pressure to build up to governor cut-out pressure. Note the cut-out pressure reading on the test gauge. Apply the brakes repeatedly and note the governor cut-in pressure. If the cut-out pressure is not 122 4 psi (8,6 0,3 kg/cm2) and the cut-in pressure 101 3 psi (7,1 0,2 kg/cm2), adjust the air compressor governor as follows:
GOVERNOR
1-Adjusting screw. 2-Locknut.Remove the cover on the top side of the governor and loosen the locknut of the adjusting screw. Turn the adjusting screw as required. One counterclockwise turn of the adjusting screw raises the cut-out pressure approximately 20 psi (1,4 kg/cm2). The cut-in pressure will raise or lower accordingly.If adjusting the governor does not change the cut-out pressure, check for a malfunction in the air compressor unloading valves. If adjusting the cut-out to cut-in pressure differential is incorrect, check for a malfunction in the air compressor governor.Governor Override Valve (If Equipped)
With the engine running at high idle and the air compressor at cut-out pressure, depress the governor override valve. The air reservoir pressure should increase beyond the normal cut-out pressure. If it does not, check the governor override valve for excessive leakage.Safety Relief Valve
Relieve all pressure from the reservoirs and remove the safety relief valve. Connect the valve, the test gauge and the pipe tee to a 9S5800 Pump Group. Apply pressure on the valve. The valve should open at 150 psi (10,5 kg/cm2). Adjust the valve by loosening the locknut and turning the adjusting screw.
SAFETY RELIEF VALVEEmergency Brake Control Valve
Start the 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 knob pops out and the emergency brakes apply. The knob should pop out when the air reservoir pressure reaches 40 5 psi (2,8 0,4 kg/cm2).Install a new valve if the knob fails to pop out.
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 inversion valve (1) may be checked by noting the reservoir pressure at which the valve releases