4 - 36
S-40 • S-45
Part No. 102521
October 2013
Section 4 • Repair Procedures
MANIFOLDS
7-2
Valve Adjustments -
Function Manifold
How to Adjust the System
Relief Valve
Note: Perform this procedure with the boom in the
stowed position.
1 Connect a 0 to 5000 psi / 0 to 350 bar pressure
gauge to the
PTEST
port on the function
manifold.
2 Start the engine from the ground controls.
3 Hold the function enable/rpm select toggle
switch to the high idle position. Activate and
hold the boom retract toggle switch with the
boom fully retracted.
4 Observe the pressure reading on the pressure
gauge. Refer to Section 2,
Specifications.
5 Turn the engine off. Use a wrench to hold the
relief valve and remove the cap (item AQ).
6 Adjust the internal hex socket. Turn it clockwise
to increase the pressure or counterclockwise to
decrease the pressure. Install the relief valve
cap.
Tip-over hazard. Do not adjust
the relief valve higher than
specified.
7 Repeat steps 2 through 5 and recheck relief
valve pressure.
8 Remove the pressure gauge.
Property of American Airlines