HEAD 9J0497 - Caterpillar

Illustration 2 g00343972
Circuit diagram (1) Swing Motor (2) Connector (3) Tee (4) Makeup line (5) Main Control Valves (6) Cap (7) Portable Hydraulic Tester (8) Pilot Line (9) Pilot Oil Manifold (10) Pressure Tap (11) Pressure Gauge (12) Pilot Pump (13) Multitach group (14) Engine
Illustration 3 g00365393
Top of main control valves (8) Pilot line
Illustration 4 g00365355
Pilot oil manifold compartment (9) Pilot oil manifold (10) Pressure tap (15) Pilot relief valve
Illustration 5 g00344084
Portable hydraulic tester (flow meter) (7) Portable hydraulic tester (flow meter) (13) Multitach group (16) Valve (flow meter)Preparation
To prevent personal injury or equipment damage from failure of the hydraulic test equipment or associated circuit components because of blocked pump flow, make sure that the test equipment valves are fully open before starting the engine.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. 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 in Caterpillar machines.Dispose of all fluids according to local regulations and mandates.
Position the machine on level ground.
Stop the engine.
Release the pressure in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic System Pressure - Release".
Install the following tools in accordance with the circuit diagram. Refer to Illustration 2.
Install 6000 kPa (870 psi) pressure gauge (11) at pressure tap (10) on pilot oil manifold (9) .
Install multitach group (13) on engine (14) .
Remove pilot line (8) from the connector that is located on top of main control valves (5). Install cap (6) on the connector.
Disconnect makeup line (4) from connector (2) of swing motor (1) .
Install tee (3) at connector (2) .
Connect makeup line (4) to tee (3) .
Install portable hydraulic tester (7) between pilot line (8) and makeup line (4) .
Start the engine.
Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.Reference: Make reference to Testing and Adjusting, "Operational Checks" for engine rpm settings.
Increase the hydraulic oil temperature to 55° 5°C (131° 9°F).Test
Turn valve (16) on portable hydraulic tester (7) clockwise until pressure gauge (11) at pressure tap (10) shows a reading of 4100 200 kPa (595 29 psi).
Record the pilot pump flow at 4100 200 kPa (595 29 psi) in the following table.
Table 1
Test Data For Pilot Pump Flow
4100 kPa (595 psi)    
Oil Temperature °C (°F)        
Engine speed (rpm)        
Flow measured liter/min (US gpm)     Upper pump        
Lower pump    
Flow corrected liter/min (US gpm)     Upper pump        
Lower pump    
Specification for pump flow liter/min (US gpm)     New    
37 2 (9.8 0.5)    
Service Limit
31 (8.2)    Note: Specifications for pump flow are based on an engine speed of 1800 rpm. To get more accurate test results, measured flow should be corrected