Setting Hydraulic Manifold Pressures; Main Relief Valve - Upright MX19 Service And Parts Manual

Section 3 - Service & Repair
S
E T T I N G
W A R N I N G
!
The hydraulic oil may be of sufficient temperature to cause burns. Wear safety gloves and safety glasses
when handling hot oil.
The oil in the hydraulic system is under very high pressure which can easily cause severe cuts. Obtain
medical assistance immediately if cut by hydraulic oil.
NOTE: Check the hydraulic pressures whenever the pump, manifold or relief valves have been serviced or replaced
M R
AIN ELIEF
1. Operate the hydraulic system 10 to 15 min-
utes to warm the oil.
2. Remove the cap or loosen the locknut on the

Main Relief Valve.

3. Install a 0-207 bar (0-3000 psi) pressure
gauge to the gauge port.
4. Turn the Chassis Keyswitch to CHASSIS and
elevate the machine fully.
5. While holding the Chassis Lift Switch to the
UP position, adjust the Main Relief Valve
until the pressure gauge reads 165 bar
(2400 psi).
6. Release the Chassis Lift Switch.
7. Replace the cap, or tighten the locknut on
the Lift Relief Valve, and torque to 8N-m
(6 ft-lbs).
8. Lower the platform.
503727-002
H M
Y D R A U L I C
!
V
ALVE
P
A N I F O L D R E S S U R E S
CHECK VALVE (POTHOLE)
CROSS LINE RELIEF
VALVES (DRIVE)
Hydraulics
Figure 3-9: Hydraulic Manifold
MAIN RELIEF VALVE
RELIEF VALVE
(STEERING)
FLOW RESTRICTOR
PRESSURE RELIEF
(STEERING)
(MAIN LIFT)
Page 3-13