PUMP G.-WATER 4M8222 - Caterpillar

Remove the dust cap and install a 6890 kPa (1000 psi) pressure gauge onto the test fitting on the manifold.
Start the engine.
Run the engine at low idle. Record the pressure that is displayed on the pressure gauge.
Run the engine at high idle. Record the pressure that is displayed on the pressure gauge.
Run the engine at high idle and operate the trailer high pressure system. Record the pressure that is displayed on the pressure gauge.
Shut off the engine.
Remove the steering frame lock.All the recorded pressures should be in the range that is specified by the manufacturer of the trailer high pressure system.Gear Pump (Trailer High Pressure System and Cooling Oil) - Test
Ensure that the oil is at operating temperature. Refer to Testing and Adjusting, "General Information" for information on warming the oil.Park the machine on a level surface. Move the parking brake control to the ENGAGED position and move the hoist control to the HOLD position. Shut off the engine.If there is a problem with the gear pump, the operating times for the trailer high pressure system might be incorrect. If there is a problem with the gear pump, the system pressure may be incorrect.
Illustration 26 g01164763
The gear pump is located beneath the cab.
Test the pressure for the hoist system. Refer to Systems Operation, Testing and Adjusting, "Trailer High Pressure System Pressure - Test". If the system pressure is incorrect and the system pressure cannot be corrected by adjustment, there may be a problem with the gear pump.
If the gear pump is malfunctioning due to damage, the gear pump must be replaced.Refer to Disassembly and Assembly, RENR5140, "Gear Pump (Hoist) - Remove" and Disassembly and Assembly, RENR5140, "Gear Pump (Hoist) - Install", as an example of removing and installing the gear pump.Specifications
255-3539 Gear Pump
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Gear pump (1) is made of two gear pumps built in tandem. Gear pump (1a) supplies hydraulic oil to the service brake cooling system. Gear pump (1b) supplies hydraulic oil to the trailer high pressure system.Gear Pump (1a) (Service Brake Cooling System)
Maximum pressure ... 20700 kPa (3000 psi)Flow rate per revolution at 6900 kPa (1000 psi) and 65 °C (150 °F) ... 181 cc (11 in3)Flow per minute at 700 RPM ... 126700 cc (7730 in3)Flow per minute at 2105 RPM ... 381000 cc (23250 in3)Gear Pump (1b) (Trailer High Pressure System)
Maximum pressure ... 31000 kPa (4500 psi)Flow rate per revolution at 6900 kPa (1000 psi) and 65 °C (150 °F) ... 45 cc (2.75 in3)Flow per minute at 700 RPM ... 31500 cc (1920 in3)Flow per minute at 2105 RPM ... 94725 cc (5780 in3) 271-5451 Cold Oil Manifold
Illustration 28 g01163619
(1) 126-6099 Relief Valve 126-6099 Relief Valve (Service Brake Cooling)
Illustration 29 g01163620
The setting for the cold oil relief valve at an oil flow of 38 4 L/min (10 1 US gpm) ... 790 30 kPa (115 5 psi) (1) Torque for plug 105 20 N m (80 15 lb ft) (2) Torque for testing 160 30 N m