Genie GTH-636 Service Manual page 160

Section 5 • Troubleshooting
TROUBLESHOOTING
10 Activate the boom up and boom down
functions.
Result: The machine functions correctly.
Replace the check valves of the dual pilot
check manifold (schematic items CA and CB).
Result: The machine does not function
correctly. Proceed to step 11.
11 Separate the hoses connected together in steps
7 and 8, and install them into the correct ports
of the dual pilot check manifold. Torque to
specification. Refer to Section 2, Specifications.
Bodily injury hazard. Spraying
hydraulic oil can penetrate and
burn skin. Loosen hydraulic
connections very slowly to allow
the oil pressure to dissipate
gradually. Do not allow oil to
squirt or spray.
12 Start the engine and allow the engine to idle.
13 Lower the boom to the stowed position.
14 Stop the engine.
15 Tag and disconnect the lower supply hose to
the lift cylinder at the exhaust side of the
machine.
Bodily injury hazard. Spraying
hydraulic oil can penetrate and
burn skin. Loosen hydraulic
connections very slowly to allow
the oil pressure to dissipate
gradually. Do not allow oil to
squirt or spray.
16 Start the engine and allow the engine to idle.
17 Activate the boom down function.
Result: Fluid is leaking from the open port of the
cylinder. The cylinder has internal leakage.
Replace the seals inside the cylinder.
5 - 12 GTH-636 • GTH-644 • GTH-842 • GTH-844 • GTH-1048 • GTH-1056
Fork Level Hose Blowout
1 Remove the load from the forks.
2 Tag and disconnect the hydraulic hoses from
the boom at ports C1 and C2 of the dual pilot
check manifold. Plug the hoses.
3 Using a jumper hose, connect together ports C1
and C2 and torque to specification. Refer to
Section 2, Specifications.
Bodily injury hazard. Spraying
hydraulic oil can penetrate and
burn skin. Loosen hydraulic
connections very slowly to allow
the oil pressure to dissipate
gradually. Do not allow oil to
squirt or spray.
4 Start the engine and allow the engine to idle.
5 Activate the boom down function and lower the
boom to the stowed position.
Note: Once the hoses are replaced, the circuit
must be bled. Refer to Repair Procedure 1-3, How
to Bleed the Lift/Tilt Circuit.
June 2007
REV B
Part No. 97487