GEAR-PLANETARY 2920256 - Caterpillar

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.
Oil for the pilot system comes from the fan pump for the hydraulic fan circuit.Pressure of the pilot oil depends on the engine temperature.
Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.
Lower the bulldozer and the ripper to the ground.
Stop the engine.
Turn the engine start switch key to ON position.
Move the bulldozer and the ripper control lever to all of the positions.
Turn the key to OFF position.
Assemble the pressure gauge, the hose, and the coupler assembly.
Remove the floorplate from the machine.
Illustration 2 g02789552
Air-To-Air Aftercooled (ATAAC) control valve (1) Pressure tap for Hydraulic Fan Pump Discharge (HFPD) (2) Adjustment screw (restrictor valve)
Illustration 3 g02789562
Electro-hydraulic valve (3) Pressure tap for hydraulic pilot supply (HPS) (4) Adjustment screw for hydraulic pilot supply (HPS) (engine on) (5) Adjustment screw for hydraulic pilot supply (HPS)(engine off)
Connect the coupler assembly with the pressure gauges to the Hydraulic Fan Pump Discharge (HFPD) and the hydraulic pilot supply (HPS).
Install the floorplate.
Start the engine and run the engine at low idle.
Adjust HFPD pressure (1) on the restrictor valve (2) to 4130 170 kPa (600 25 psi).
Increase the engine speed to high idle.
Turn the implement lockout switch to the ON position.
Adjust HPS pressure (3) on the pressure reducing valve (4) to 3930 170 kPa (570 25 psi).
Position the blade and the ripper to full RAISE position.
Stop the engine and monitor HPS pressure (3) .
Move the bulldozer control lever from NEUTRAL position to RAISE position and hold for three seconds. This will drain the pilot pressure in the accumulator.
Release the bulldozer control lever into NEUTRAL position.
Adjust HPS pressure (3) on the pressure reducing valve (5) to 1800 200 kPa (260 30 psi).
Lower the implements to ground.Accumulator Testing and Charging
Hot hydraulic oil under high pressure can remain in the components of the hydraulic system or the power train system after the engine has been stopped. The uncontrolled release of the hydraulic oil can cause sudden machine movement and can also result in the following conditions:
Burns
The penetration of body tissue
Other personal injury
DeathIf hydraulic oil penetrates body tissue, the injury must be treated immediately by a doctor who is familiar with this type of injury. Use a board or a piece of cardboard to check for a hydraulic oil leak. Make sure that all of the attachments have been lowered to the ground and that all trapped pressure has been released from the hydraulic system and the power train system. Also, make sure that the hydraulic oil is cool before the removal of any components or lines.