4 - 36 S-40 • S-45 Part No. 102521October 2013Section 4 • Repair ProceduresMANIFOLDS7-2Valve Adjustments -Function ManifoldHow to Adjust the SystemRelief ValveNote: Perform this procedure with the boom in thestowed position.1 Connect a 0 to 5000 psi / 0 to 350 bar pressuregauge to the PTEST port on the functionmanifold.2 Start the engine from the ground controls.3 Hold the function enable/rpm select toggleswitch to the high idle position. Activate andhold the boom retract toggle switch with theboom fully retracted.4 Observe the pressure reading on the pressuregauge. Refer to Section 2,Specifications.5 Turn the engine off. Use a wrench to hold therelief valve and remove the cap (item AQ).6 Adjust the internal hex socket. Turn it clockwiseto increase the pressure or counterclockwise todecrease the pressure. Install the relief valvecap.Tip-over hazard. Do not adjustthe relief valve higher thanspecified.7 Repeat steps 2 through 5 and recheck reliefvalve pressure.8 Remove the pressure gauge.Property of American Airlines
