Genie GTH-636 Service Manual page 155

June 2007
REV B
Check the Controller Relief (drop block)
Manifold
5 Turn the key switch to the on position. Do not
start the engine.
6 Using a wrench, check for magnetism in the
solenoid valve of the controller relief manifold.
Touch a wrench to the end of the valve.
Result: The wrench sticks to the valve. The coil
is good. Proceed to step 9.
Result: The wrench does not stick to the valve.
Proceed to step 7.
Note: The controller relief manifold is secured to
the hoses inside the frame rail next to the
operator's compartment.
Note: A fast way to determine if a valve coil is
functioning correctly is to touch a wrench to the
end of the valve when the coil is activated. When
energized, the valve will magnetize and the wrench
will stick to the valve; turn the power off and the
wrench will fall.
7 Using a multimeter, check for power at the
valve coil.
Result: Power is present at the coil. Proceed to
step 8.
Result: Power is not present at the coil. Repair
the wire circuit to the coil.
8 Check for continuity in the ground wire circuit
from the controller relief valve coil to ground.
Result: The ground circuit has continuity.
Replace the valve coil.
Result: The ground circuit does not have
continuity. Repair the ground wire circuit to the
coil.
Part No. 97487 GTH-636 • GTH-644 • GTH-842 • GTH-844 • GTH-1048 • GTH-1056
9 Tag and disconnect the two smaller hydraulic
hoses at the controller relief manifold. Connect
the hoses together and torque to specification.
Refer to Section 2, Specifications.
Note: Do not remove the three larger hoses from
the manifold.
10 Start the engine and allow the engine to idle.
Test a boom function.
Result: The boom functions correctly. The
controller relief valve (schematic item OA) is
faulty. Replace the valve.
Result: The boom does not function correctly.
The controller relief valve is good. Proceed to
step 11.
11 Stop the engine.
12 Install the hoses, disconnected in step 9, into
the controller relief manifold. Torque to
specification. Refer to Section 2, Specifications.
Check the Joystick
13 Locate the hose installed into port P of the
joystick. Tag the hose.
14 Tag, disconnect and plug all hydraulic hoses
installed into the joystick except for the hose at
port P of the joystick.
15 Start the engine and allow the engine to idle. Do
not move the joystick.
Result: Oil does not flow from any port. The
joystick is functioning correctly.
Result: Oil flows from one or more ports of the
joystick. The joystick is faulty. Repair or replace
the joystick.
Section 5 • Troubleshooting
TROUBLESHOOTING
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