JLG 800S Service Manual - Manual (Page 282)

SECTION 5 - HYDRAULICS
5-12 – JLG Lift – 3121139
HIGH PRESSURE RELIEF
1. Install a high pressure gauge at the “M1” port of the
main valve block.
2. Activate telescope in. The gauge should read 2800
psi.
3. To make an adjustment to this pressure, go back to
the engine compartment to the function pump. The
high pressure relief adjustment is the lower one of
the (2) on the compensator. To adjust this, a 4 mm
and 6 mm allen wrench will be needed. The adjust-
ment screw is facing the front of the pump, or toward
the engine.
a. First, using the 4 mm wrench, loosen the set
screw on the side of the compensator (facing
you) which is in line with the adjustment screw.
This is a jam nut screw which holds the main
adjustment from turning. Loosen it 1 turn.
b. Next, using the 6 mm wrench adjust the main
adjustment clockwise to increase or counter-
clockwise to decrease. This adjustment will be
re-set at the end of this procedure to 2500 psi
(172 Bar). This is the maximum relief pressure
for all functions governed by this pump.
Adjustments Made at the Main Valve Block
TELESCOPE OUT
1. Install a high pressure gauge at the “M3” port of the
main valve block.
2. Activate Telescope out. The gauge should read 2500
psi (172 Bar).
3. The relief valve is located directly below the M3 port.
Turn clockwise to increase, counterclockwise to
decrease.
SWING LEFT AND RIGHT
1. Lock the Turn-table lock pin.
2. Install the hi-pressure gauge at M2.
3. Activate swing, the gauge should read 1700 psi (117
Bar).
4. The adjustment cartridge is located right above the
M2 port. Turn clockwise to increase, counterclock-
wise to decrease.
STEER
1. Install a hi-pressure gauge at port M4. Activate steer
left or right. The gauge should read 2500 psi (172
Bar).
2. The relief valve is located right above port M4. Turn
clockwise to increase, counterclockwise to
decrease.