Service and Repair Manual April 2017Hydraulic Pump52 GTH-1056 Part No. 12781454 Loosen the set screw for the standby pressureadjustment screw.1 standby pressure adjustment screw2 set screw3 hydraulic supply line (from tank)5 Adjust the function pump standby pressure.Turn the adjustment screw clockwise toincrease the pressure or counterclockwise todecrease the pressure. Tighten the set screw.6 Turn the engine off and remove the pressuregauge.Bodily injury hazard. Sprayinghydraulic oil can penetrate andburn skin. Loosen hydraulicconnections very slowly to allowthe oil pressure to dissipategradually. Do not allow oil tosquirt or spray.How to Adj ust the Functi on Pump Press ure Compens atorHow to Adjust the Function PumpStandby PressureNote: Two people will be required to perform thisprocedure.1 Connect a 0 to 5000 psi / 0 to 350 barpressure gauge to test port 'TP' on the primaryfunction manifold. Refer to Primary FunctionManifold Components.2 Start the engine and allow the engine to run atlow idle.3 Fully retract the boom.4 Continue to activate the boom retract functionand observe the pressure reading on thepressure gauge.Result: The pressure gauge reads3190±50 psi / 220±3.4 bar. The pump isfunctioning correctly. Proceed to step 7.Result: The pressure gauge fails to read3190±50 psi / 220±3.4 bar. The pressuresetting needs to be adjusted. Proceed to step5.
