SHAFT 4F1529 - Caterpillar

Accumulator Precharge Pressure
To check and adjust the accumulator precharge pressure using the CAT charging assembly 7S5437.1. Park the truck on level ground and stop the engine.2. Use the suspension control valve hand lever to lower the suspension fully. This allows the oil at the bottom of the piston accumulator to return to tank. Secure the lever in the "lower" position.3. Remove the guard and protective cap from the accumulator gas valve.
Front Suspension Accumulator Gas Valve
Rear Suspension Accumulator Gas Valves 1. Low Pressure Accumulator2. High Pressure Accumulator
Charging Equipment4. Use the 0-14000 kPa (0-2000 p.s.i.) gauge (3) when charging the front suspension accumulator or the rear suspension high pressure accumulator. Use the 0-7000 kPa (0-1000 p.s.i.) gauge when charging the rear suspension low pressure accumulator and ensure that valve (2) is closed.5. Attach connector (4) to the accumulator gas valve.6. Turn valve (5) clockwise until it is screwed fully down. The accumulator precharge pressure will be shown on the gauge (3).7. If the pressure is high remove the quick disconnect coupling (1) and crack valve (2) until the gauge registers the correct value.8. If the pressure is low attach the quick disconnect coupling (1) to valve (2) and attach regulator (6) to the nitrogen cylinder.9. With valve (2) closed, open the nitrogen cylinder valve and adjust screw (7) until gauge (8) registers the correct precharge pressure.10. Open valve (2), allow the accumulator to charge and close valve (2). If the pressure registered on the gauges (3 & 8) is the same, the accumulator is properly charged. Repeat if necessary until the gauge readings agree.11. Close valve (2) and the nitrogen cylinder valve.12. Turn valve (5) fully counter-clockwise. Remove the test equipment.13. Start the engine, release the hand lever and allow the suspension to return to the 'level ride' position.Charging A Rebuilt Accumulator
It is necessary to remove all the air from the nitrogen end of the accumulator. When the accumulator is rebuilt, put 2 litres (0.50 U.S. gallons) of hydraulic oil in the nitrogen end. This oil is used to vent the air from the accumulator and to lubricate the piston top seal. Install the accumulator on the truck leaving the hydraulic line disconnected and charge as follows:1. Use the same CAT charging equipment as used to charge the accumulator.2. Attach connector (4) to the accumulator gas valve. Turn valve (5) clockwise until it is fully screwed down.3. With valve (2) closed, open the nitrogen cylinder valve and adjust screw (7) until gauge (8) registers approximately 690 kPa (100 p.s.i.).4. Open valve (2), allow the accumulator to charge and close valve (2). This will move the piston down to the bottom of the accumulator to exhaust air from below the piston. Attach the hydraulic connection to the accumulator.5. Remove the quick disconnect coupling (1) and crack valve (2) to release the gas pressure above the piston. Start the engine and use the hand lever on the suspension control valve to raise the suspension. The piston in the accumulator will rise and