Adjust the boom hoist, retract, and telescope reliefs using the following procedures.
Adjust the boom hoist relief by loosening jam lock nut on relief valve. Adjust valve with
adjusting screw while booming up or down over relief withe engine at maximum governed
rpm. Screw in to increase pressure setting; out to decrease it. Retighten lock nut when
proper setting is obtained.
EXTEND/RETRACT RELIEFS
The initial range has been preset. Adjustment is accomplished by loosening the jam nut
and either turning the adjusting screw in to increase pressure or backing it off to lower
pressure. Retighten the jam nut when the desired pressure is obtained.
Set extend/retract by the following procedure:
First, retract the boom completely and continue to retract over relief with the engine
running at full governed rpm. Initially, set the retract port relief valve (located on spring cap
end of telescope section) to obtain a reading according to above chart. Then turn it an
additional 1/2 turn clockwise.
MAIN WINCH RELIEF
Check the winch relief setting using the following procedure:
1.
Attach a pressure gauge to the test port on the mid-section inlet port.
2.
Disconnect and plug the brake line at the piston housing on the winch.
3. Restart the engine and run at high idle speed.
4. Winch and hold the lever in the “lower” position while obtaining a reading. See chart
below for proper settings. The main & auxilary winch relief are combined into one valve
bank assembly as shown below. It is adjusted in the same manner as the boom relief.
479P/N 12261-683 REVISED: January 2015
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