JLG 600SC_660SJC Service Manual - Manual (Page 183)

SECTION 5 - HYDRAULICS
3121607 – JLG Lift – 5-39
Placing Pump Back Into Service
1. If shop test stand is available, use the following proce-
dure for testing rebuilt pumps:
a. Mount pump on test stand. Make sure proper level
of clean oil is available in 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, use the following proce-
dure for testing rebuilt pumps:
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. Operate control valve and 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.
5.7 VARIABLE PUMP
Ports and Pressure Gauges
Proper servicing of pumps and motors requires pressure mea-
sured and monitored at various hydraulic circuit points. The
Series 42 pump has several locations at which to take these
measurements. The following outlines show gauge port loca-
tions, and gauge and fitting size for each port.
NFPE Control
The 3-position FNR control, and electric and hydraulic non-
feedback proportional (NFPE and NFPH) controls are non-
feedback type controls. FNR and NFPE controls consist of
pump housing mounted modules. Hydraulic input for NFPH is
received through ports on top of pump [9/16–18 SAE O-ring
fitting].
Non-feedback controls are factory set. Control modules can be
removed to clean ports and change O-rings.
FNR and NFPE orifice plugs are located inside the servo piston
covers. NFPH orifice plugs are located in the NFPH ports. Ori-
fice 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