Genie GTH-844, Service And Repair Manual

Page: 72 / 187

Service and Repair Manual April 2017
Manifolds
60 GTH-844 Part No. 1272854
How t o Set t he R ear Loc k-up Sys tem Pressur e
How to Set the Rear Lock-up
System Pressure
Note: Be sure that the hydraulic oil level is visible in
the inspection glass of the hydraulic tank.
1 Install a 0 to 1000 psi / 0 to 100 bar pressure
gauge into test port 'TP' at the top of the
primary function manifold. Refer to Primary
Function Manifold Components.
2 Start the engine. Allow the engine to idle after
warming the engine to operating temperature.
3 Without operating any machine controls,
observe the reading on the pressure gauge.
Result: The pressure gauge reads 450 ±25 psi
/ 31 ±1.7 bar. The pump is functioning
correctly.
Result: The pressure gauge fails to read 450
±25 psi / 31 ±1.7 bar. The pressure setting
needs to be adjusted. Refer to Repair
Procedure,
How to Adjust the Function Pump
Pressure .
4 Turn the machine off. Remove the pressure
gauge from the test port.
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.
5 Install a 0 to 500 psi / 0 to 50 bar pressure
gauge into test port 'TR' at the top of the
secondary function manifold, Refer to
Secondary Function Manifold Components.
6 Start the engine. Allow the engine to idle.
Result: The pressure gauge reads 50 psi /
3.4 bar. The pressure setting is correct.
Proceed to step 11.
Result: The pressure gauge fails to read 50 psi
/ 3.4 bar. The pressure setting needs to be
adjusted. Proceed to step 7.
7 Turn the machine off. Hold the rear lockup
pressure reducing/relief valve with a wrench
and remove the cap (schematic item PR2).
8 Adjust the internal hex socket. Turn it
clockwise to increase the pressure or
counterclockwise to decrease the pressure.
Component damage hazard. Do
not adjust the relief valve
pressures higher than
specifications.
9 Install the relief valve cap.
10 Repeat this procedure beginning with step 6.
11 Turn the machine off. Remove the pressure
gauge from the test port.
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.