HEADREST 1175976 - 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.
Personal injury or death can result from machine articulation or movement.Machine frames can move and a person can be crushed.Connect the steering frame lock link between the front and rear frames before working on machine.
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, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Before any tests are performed, visually inspect the complete hydraulic system for oil leaks and damaged parts. Refer to Testing and Adjusting, "Visual Inspection". Before any tests are performed, prepare the machine for troubleshooting. Refer to Testing and Adjusting, "Machine Preparation for Troubleshooting".
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.
Lower the work tool to the ground. Stop the engine.
Engage the parking brake.
Connect the steering frame lock.
Place chocks in front of the wheels and behind the wheels.
Raise the hood.
Illustration 1 g00627080
Location of the test port for the work tool pump (1) Test port
Install the 8T-0860 Gauge to the test port (1) with the 1U-5755 Hose. Secure the hydraulic line so that the pressure gauge can be viewed by the operator during the test.
Fasten the seat belt. Start the engine.
Move the work tool to the full TILT BACK position.
Run the engine at high idle.
Do not stall the hydraulic system for more than 10 seconds. If necessary, release the work tool from the stall condition and wait 30 seconds before you repeat the following step.
Move the work tool to the full LOWER position. Hold the work tool at that position until a stall condition exists. Record the pressure at the stall condition. The pressure should be 24500 1500 kPa (3550 220 psi).
Release the work tool from the stall condition. Reduce the engine speed to low idle. Tilt the work tool until the work tool is parallel with the ground. Stop the engine. If the pressure reading is within specifications, proceed to step 21. If the pressure reading is not to specifications, proceed to step 13.
Turn the engine start switch key to the ON position.
Move the pilot valves to all positions in order to release the pressure in the hydraulic system.
Turn the engine start switch key to the OFF position.
Illustration 2 g00629675
Location of the main relief valve
Illustration 3 g00627216
(2) Main relief valve (3) Cap
Remove cap (3) from main relief valve (2) .
Illustration 4 g00627217
(4)