JLG 3248RS/10RS Service Manual - Manual (Page 86)

SECTION 4 - HYDRAULICS
4-6 – JLG Lift – 3121273
4.4 LIFT PRESSURE SETTING PROCEDURE
1. Place 120% of the rated load of the machine on the
platform.
2. Increase lift pressure to raise the platform to full
height.
3. Adjust the pressure setting screw on lift relief valve
to reach the proper lift pressure per model as listed
in Table 4-2.
Alternate Lift Pressure Setting Procedure -
(if 120% load or high ceiling is not available):
1. Install adapter from table into M-port or P1-port on
pump (see Figure 4-2.) and attach pressure gauge.
2. Remove the solenoid from the lift valve.
3. Activate the lift function from the ground or platform
and adjust the pressure setting screw on lift relief
valve to reach the proper lift pressure per model as
listed in Table 4-2.
4. Remove the pressure gauge from port M or P1 and
replace plug.
5. Replace the solenoid on the lift valve.
4.5 CYLINDER CHECKING PROCEDURE
NOTE: Cylinder check must be performed anytime a system compo-
nent is replaced or when improper system operation is sus-
pected.
1. Using all applicable safety precautions, activate
pump motor and fully extend cylinder to be
checked.
2. Carefully disconnect hydraulic hoses from retract
port of cylinder. There will be some initial weeping of
hydraulic fluid which can be caught in a suitable
container. After the initial discharge, there should be
no further drainage from the retract port.
3. Activate pump motor and extend cylinder.
4. If cylinder retract port leakage is less than 6-8 drops
per minute, carefully reconnect hose to port and
retract cylinder. If leakage continues at a rate of 6-8
drops per minute or more, cylinder repair must be
made.
NOTE: Steps 5 through 7 for Steer Cylinder Only.
5. With cylinder fully retracted, shut down machine
power and carefully disconnect hydraulic hose from
cylinder extend port.
6. Activate pump motor and retract cylinder. Check
extend port for leakage.
7. If extend port leakage is less than 6-8 drops per min-
ute, carefully reconnect hose to extend port, than
activate cylinder through one complete cycle and
check for leaks. If leakage continues at a rate of 6-8
drops per minute or more, cylinder repairs must be
made.
Table 4-2. Lift Pressure Settings
Model Lift Relief Steer Relief
1932RS/6RS
2300 psi ± 50 psi
(159 bar ± 3.5 bar)
1000 psi
(69 bar)
3248RS/10RS
2500 psi ± 50 psi
(172 bar ± 3.5 bar)
1000 psi
(69 bar)
Table 4-3. Pressure Fitting Adapter
PORT JLG PART #
P1 300057 - JIC
M
300017 - JIC
2221222 - Quick Disconnect