Oshkosh JLG 400S, Service And Maintenance Manual

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SECTION 5 - HYDRAULICS
5-18 – JLG Lift – 3120895
cartridge on the jib block. Turn clockwise to increase,
counterclockwise to decrease.
6. Articulating Jib Down;
Install a high pressure gauge on the “M” port of the jib
block, located on the left side of the main valve. Activate
jib down, reading should be 1200 psi. The down relief
valve is the back cartridge on the jib block. Turn clockwise
to increase, counterclockwise to decrease.
7. The Bang-Bang Main Relief Valve;
This valve will need to be reset from 3000 psi to 2500 psi.
Install a high pressure gauge at the port marked “M1”
located behind the tank port. Activate telescope in. Adjust
the valve to 2500 psi. This valve is located on the top of
the main valve, the 3
ard.
relief valve to the left of the tank
port. Turn clockwise to increase, counterclockwise to
decrease.
8. The Proportional Main relief valve;
Install a high pressure gauge at the port marked “M2”
located on top of the main valve in front of the tank port.
This relief valve is located on top of the main valve and is
the 4
th.
relief valve to the left of the tank port. Adjust valve
to 2750 psi. This is done by raising the boom to the end of
stroke, or removing the hoses from ports #9 and #10 of
the main valve and plugging the hoses and capping the
ports. Activate lift up to read 2750 psi. Turn clockwise to
increase and counterclockwise to decrease. Leave the
hoses plugged and ports capped for lift down.
9. Lift Down;
Install a high pressure gauge at the port marked “M2”,
located on top of the main valve in front of the tank port.
The relief valve is located on top of the main valve and is
the 6
th.
relief valve to the left of the tank port. This relief
valve should be adjusted to 1600 psi. Activate lift down.
Turn clockwise to increase, counterclockwise to decrease.
Connect the hoses to the lift section.
10. Swing;
Left and right swing are done with (1) adjustment. Install a
high pressure gauge at the port marked “MS”, located on
the front face of the main valve at far left corner. The relief
valve is located on top of the main valve and is the #7
relief valve to the left of the tank port. adjust relief valve to
1600 psi. This can done by using the turntable lock, or
removing the wires from the swing valve, or by removing
the hoses from ports #11 and #12 of the main valve,
plugging the hoses and capping the ports. Activate swing
in either direction. Turn clockwise to increase, counter-
clockwise to decrease.
5.5 HYDRAULIC MOTOR REPAIR (H SERIES
CHAR-LYNN)
Cleanliness is extremely important when repairing these
motors. Work in a clean area. Before disconnecting lines,
clean port area of motor. Remove key when used. Check
shaft and key slot. Remove burrs, nicks, and sharp edges.
Before disassembly, drain oil from motor. Then plug ports
and thoroughly clean exterior of motor.
Although not all drawings show the motor in a vise, we
recommend that you keep the motor in a vise during dis-
assembly. Follow the clamping procedure explained
throughout the manual.
Disassembly
1. Place motor in a vise and clamp across edge of
flange with output shaft down. When clamping, use
protection devise on vise such as special soft jaws,
pieces of rubber or board.
2. Remove cap screws and seal washers (when appli-
cable).