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Western Shotcrete Equipment, Inc.
2.2 Valves
Setting the main relief valve 83301 (Sun RPGC-FCN)
•Loosen locking nut with a 9/16” wrench.
•Turn adjuster all the way out.
•Start engine, place in pressure test mode, turn pump on and observe main hydraulic pressure gauge.
•Turn adjuster in until the pressure gauge stops climbing. (It should stop climbing when it reaches the pump
setting at 3800 psi.)
•Turn adjuster In an additional 1/2 turn and tighten locking nut.
Setting the Unloader/Check valve 83410 (Sun QCDB-LAN) and the Unloader/Relief valve. 83411 (Sun RVCA-
LAN)
•Loosen locking nuts with a 9/16” wrench.
•Screw top valve (Unloader/Check-83410) adjuster all the way in using a 3/16” hex key.
•Screw the bottom valve (Unloader/Relief-83411) adjuster all the way out.
•Start engine and observe accumulator pressure gauge.
•Screw the bottom valve (Unloader/Relief) adjuster in until the accumulator gauge reads 2200~2500 psi.
•Screw the top valve (Unloader/Check) adjuster out until the pump unloads then turn out an additional 1/4
turn. You can tell when the pump unloads by three ways:
a) Listening for a slight clicking noise in the Unloader/Relief valve.
b) Hearing the engine work less.
c) Seeing the accumulator charge hose relax.
• If you have difficulty determining when the pump unloads, place a 4000# gauge in-line at the pump output.
When the pump unloads the gauge will drop from 2500 psi to near 0 psi.
•Tighten locking nuts.
•Test operation by shifting S-Tube with the Forward/Reverse switch and observing Accumulator gauge. The
pump should promptly charge the Accumulator to 2300~2500 psi and then unload.
2.3 Cylinders
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