PUMP GP-PISTON 1877338 - Caterpillar

Dry nitrogen is the only gas approved for use in the suspension accumulators. The charging of oxygen gas in these components by accident will cause an explosion. This danger can be avoided by the use of nitrogen cylinders with standard CGA (Compressed Gas Association, Inc.) No. 580 connections. When nitrogen gas is ordered, be sure to order cylinders with CGA No. 580 connections. Do not go by color codes or other methods of identification to tell the difference between nitrogen and oxygen cylinders. In any application never use an adapter to connect your nitrogen charging group to a valve outlet used on nitrogen, oxygen or other gas cylinders. Be sure you use dry nitrogen. Use a 7S-5437 charging assembly to check or adjust the precharge pressure.
1. Park the machine, unladen, on a hard level surface, engage the parking brake and stop the engine.2. Block the front and rear of the trailer wheels and then disengage the parking brake.3. Fully lower the front suspension. See the topic "To adjust rear suspension ride height" which details how to lower the front and rear suspension. 4. Remove guard (1) and protective cap (2) from accumulator gas valve (3).
Typical5. Use the 0-14 000 kPa (0-2000 psi) gauge (6).6. Ensure that valve (5) is closed.7. Attach connector (8) to the accumulator gas valve.8. Turn valve (7) clockwise until it is screwed fully down. The accumulator precharge pressure will be shown on gauge (6).9. If the pressure is high remove the coupler (4) and open valve (5) slightly until the gauge registers the correct value.10. If the pressure is low, attach coupler (4) to valve (5) and attach regulator (10) to the nitrogen cylinder.11. With valve (5) closed, open the nitrogen cylinder valve and adjust screw (11) until gauge (9) registers the correct precharge pressure.12. Open valve (5) and allow the accumulator to charge.13. Have an assistant open the suspension valve hand lever to ensure no back pressure has built up in the system close valve (5).14. If the pressure registered on the gauges is the same the accumulator is correctly charged. Repeat steps 11 through 14 until the gauge readings agree.15. Close valve (5) and the nitrogen cylinder valve.16. Turn valve (7) fully counterclockwise and remove the test equipment.17. Apply soapy water to the accumulator gas valve and check for leaks. If completely leak free install the protective cap and guard.18. Set the suspension height as described in the topics "To adjust rear suspension ride height" and "To increase front suspension rode height".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 liter (0.50 U.S. Gal) 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.Use the 7S5437 charging assembly and proceed as follows:1. Install the accumulator on the machine but do not connect the hydraulic line.2. Attach connector (8) to the accumulator