Broderson IC-100-3A, Operation And Maintenance Manual

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BOOM AND OUTRIGGER CIRCUIT:
The relief valve pressure setting at the inlet for boom control sections is 3000 PSI (207
bar). This pressure is required for all but the swing control section. Two work port relief
valves are installed in the swing section. These relief valves are set at 1500 PSI (103
bar).
The relief pressure at the inlet end of the valve can be adjusted with a wrench and an
allen wrench. Loosen the nut and tighten the threaded stem with an allen wrench to
increase pressure, and loosen the stem to decrease pressure. Lock in place with the
nut. Actuate the BOOM LOWER or TELESCOPE RETRACT function with the cylinder
fully retracted when making this adjustment.
While the pressure gauge is attached, the swing function may be checked by capping
the two work ports of the swing section and actuating the swing control lever in each
direction. If these pressures are improper, the work port relief valve can be removed
and shims added or removed as needed. Pressure is changed approximately 100 PSI
(7 bar) to 125 PSI (9 bar) for each .010" (.25 mm) shim. Part numbers for the work port
relief valves and shims:
9-340-00070 Work Port Relief Valve -- Gresen #7460-002 PS 1500 C
9-340-00032 Shim -- .010" (.25 mm) -- Gresen #0462-001
9-340-00031 Shim -- .020" (.5 mm) -- Gresen #0459-001
9-340-00030 Shim -- .040" (1 mm) -- Gresen #0458-001
BOOM CYLINDER HOLDING VALVE:
A holding valve is directly connected to the base of the boom lift cylinder barrel and to
the base of the primary telescope cylinder rod. These valves are designed to hold the
boom in position should loss of power or pressure line failure occur.
To check the boom lift cylinder holding valve, set the outriggers, place the boom in the
horizontal position over the front of the crane and raise rated load about 6 inches (15
cm) above the ground using the boom lift cylinder (not the hoist). An example of rated
load for the IC-100-3A is 5100 pounds (2200 kg) at a 16 - foot (5.0 m) load radius with
outriggers extended and the boom over the front. Turn the engine off and move the
BOOM lever to the LOWER position. If the boom moves down, adjust the holding valve.
W A R N I N G
Before working on the holding valves or plumbing to the lift cylinders, always
relieve trapped pressure by lowering the boom fully, turning off the engine, and
cycling the BOOM lever.
To adjust the holding valve, loosen the jam nuts on the adjusting screw and tighten the
screw until unpowered boom movement stops. Retighten the jam nuts. If adjusting the
valve does not help, the cylinder may have internal leakage or the valve may be
malfunctioning.