SECTION 4 - CONTROL COMPONENTS
31215825
4-21
4.8 PUMP-MOTOR ASSEMBLY - SERVICE
PROCEDURE
Hydraulic Pressure settings and Adjustment
Adjust system pressure so that platform will raise with maxi
-
mum rated capacity in platform.
The following pressure setting are factory recommended (ini
-
tial) settings;
Turning adjustment screw clockwise increases system pres
-
sure, turning screw counterclockwise decreases system pres
-
sure.
(See Figure 4-35., Hydraulic Pressure Adjustment Screw
(Machine Rear Covers Removed))
Perform pressure adjustment with oil at normal operating
temperature. If pressure is set when oil is cold, platform may
not raise rated load after soil has warmed.
Figure 4-35. Hydraulic Pressure Adjustment Screw
(Machine Rear Covers Removed)
Hydraulic Pressure Gauge Connection
ONLY OPEN HYDRAULIC SYSTEM LINES WITH THE MAST
FULLY LOWERED TO RELIEVE PRESSURE IN THE SYSTEM.
CAREFULLY LOOSEN REQUIRED FITTINGS, WEAR SAFETY
P R OT E C T I O N E Q U I PM E N T W H E N W O R K I N G W I TH
HYDRAULIC SYSTEMS.
Remove the hydraulic oil filter and install a t-fitting between
the pump and the extend line to connect a hydraulic pressure
gauge as shown in Figure 4-36., Typical Hydraulic Pressure
Gauge Installation (Hydraulic Filter Removed)
CHECK, and if necessary, ADJUST the hydraulic pressure to ini
-
tial settings shown in table at the beginning of this section.
Cycle the hydraulic system several times with the maximum
load capacity in the platform, then recheck pressure setting.
When pressure has stabilized continue to “After Filter Pressure
Check” following.
Figure 4-36. Typical Hydraulic Pressure Gauge
Installation (Hydraulic Filter Removed)
MODEL
PRESSURE
SETTING
20MVL
2000 PSI
20MSP
2800 PSI
1
2
2
3
1
4
1.
Remove Adjust Screw
Cap
2.
Pressure Adjustment
Screw
Note:
Machine rear covers must be removed to access pump
motor
1.
Pressure Gauge
Assembly
2.
Extend Line
3.
T- Fitting
4.
Return Line
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