JLG 510AJ Service Manual - Manual (Page 264)

SECTION 5 - HYDRAULICS AND HYDRAULIC SCHEMATICS
5-44 – JLG Lift – 3121181
Placing Pump Back Into Service
1. If shop test stand is available, the following procedure for
testing rebuilt pumps is recommended:
a. Mount pump on test stand making sure that the
proper level of clean oil is available in the reservoir.
Check suction line for leaks and obstructions.
b. Start pump and run for three minutes at zero pres-
sure.
c. Intermittently load pump to 500 P.S.I. for three min-
utes.
d. Intermittently load pump to 1000 P.S.I. for three
minutes.
e. Intermittently load pump to 2000 P.S.I. for three
minutes.
f. Remove pump from test stand and check for free-
ness of drive shaft. Check pump for signs of external
leakage.
2. If shop test stand is not available, the following procedure
for testing rebuilt pumps is recommended:
a. For engine driven pumps, mount pump on equip-
ment and run pump at 1/2 engine speed at zero
pressure for three minutes.
b. By operating control valve, build pressure intermit-
tently for three minutes.
c. Increase engine speed to full throttle and build
pressure intermittently for three minutes.
d. Stop engine and check pump for external leaks.
5.4 VARIABLE PUMP
Ports and Pressure Gauges
Proper servicing of pumps and motors requires that pressure
be measured and monitored at various points in the hydraulic
circuit. The Series 42 pump has several locations at which to
take these measurements. The following outlines show the
locations of the various gauge ports. The following table
shows the recommended gauge size and the fitting size for
each port.
NFPE Control
The 3-position FNR control and the electric and hydraulic non-
feedback proportional (NFPE and NFPH) controls are non-
feedback type controls. The FNR and NFPE controls consist of
modules mounted on the pump housing. The hydraulic input
for NFPH is received through ports on the top of the pump [9/
16–18 SAE O-ring fitting].
The non-feedback controls are set at the factory. The control
modules can be removed to clean the ports and change the O-
rings.
The orifice plugs for the FNR and NFPE are located inside the
servo piston covers. The orifice plugs for the NFPH are located
in the NFPH ports. Orifice plugs may be cleaned or replaced.
Table 5-2. Recommended Gauge Size
Gauge
Port
Name
Pressure
Measured
Recommended Gauge
Size
Fitting
PSI Bar
M1 & M2 System
Pressure
Ports A & B
10000 600 9/16-18 ORF
M3 Charge 1000 60 3/4-16 ORF
M4 & M5 Servo 1000 60 9/16-18 ORF
L1 & L2 Case 500 35 1-1/16-12 ORF
S Charge Pump
Inlet Vacuum
30 in. Hg Vac. 1 1-1/16-12 ORF