JLG 680S, Service And Maintenance Manual

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SECTION 5 - BASIC HYDRAULICS INFORMATION & SCHEMATICS
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STEER
1. Install a high pressure gauge at port M4. Activate steer
left or right. The gauge should read 2500 psi (172.3 bar).
2. The adjustment cartridge is located on the left face of
the valve block.
3. There are two adjustable relief valves on this face. The
steer relief is the lower one. Turn clockwise to increase,
counterclockwise to decrease.
Adjustments Made at the Platform Valve Assembly
NOTE: When replacing the level up or level down cartridge, the
function should be cycled, and then the crack pressure
value calibrated.
PLATFORM LEVEL UP
1. Install a high pressure gauge at port “M1”. Activate level
up to the end of stroke, you should read 2600 psi
(179 Bar).
2. The level up relief valve is located to the right and above
port M1. Turn clockwise to increase, counterclockwise to
decrease.
PLATFORM LEVEL DOWN
1. Install a high pressure gauge at gauge port “M2”, Acti-
vate level down to the end of stroke, you should read
1800 psi (124 Bar).
2. The level down relief valve is located to the right and
below port M2. Turn clockwise to increase, counter-
clockwise to decrease.
PUMP HI-PRESSURE RELIEF VALVE
Go back to the function pump and re-set the hi-pressure from
2800 psi (193 Bar) back to 2500 psi (172 Bar).