PISTON AS 3240384 - Caterpillar

Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.In order to prevent possible injury, perform the following procedure before testing and adjusting any of the machine hydraulic systems.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Note: The 844H Wheel Dozer and 990H Wheel Loader are equipped with two hydraulic tanks. The tank for the implement system and the brake system is located outside the cab on the right side of the machine under the floorplate. The tank for the hydraulic fan system and the steering system is located on the left side of the cab under the floorplate. If maintenance is performed on any of the hydraulic systems, the hydraulic pressure should be released from both of the hydraulic tanks.Reference: Refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced before performing the following procedure.
Illustration 1 g01205402
Brake and Implement Hydraulic Tank
(1) Filler cap
(2) Breaker relief valve To manually purge the pressure that is in the hydraulic tanks, the following procedure should be done.
Park the machine on a smooth, level surface. Engage the parking brake. Turn the ignition key to the OFF position.
In order to release the pressure in the accumulators, apply the brakes repeatedly.
Move the implement control levers through the full range of travel. This will relieve any pressure that may be present in the implement hydraulic system. Place the lift control lever in the HOLD position. Place the tilt control lever in the HOLD position.
Move the STIC steering control lever several times through the full range of motion in order to relieve the pressure in the steering system.
In order to purge the pressure that is in the hydraulic oil tanks, press the plunger on breaker relief valve (2) on each tank.