JLG 600SC_660SJC Service Manual - Manual (Page 189)

SECTION 5 - HYDRAULICS
3121607 – JLG Lift – 5-45
Charge Pump
NOTE: Disassemble charge pump to inspect and clean, or change
auxiliary shaft drive coupling.
1. Remove auxiliary pump if necessary.
2. Remove screws retaining charge pump cover to pump
housing (Torx T). Seven screws are used with “no pad” or
SAE “A” auxiliary mounting pad charge pump cover, and
six screws are used with SAE “B” auxiliary mounting pad
charge pump cover. Remove charge pump cover, gas-
ket, and cover locating pins.
3. Remove gerotor cover assembly from charge pump
cover or back of pump housing. Remove gerotor cover
O-rings. Two O-rings are used on gerotor cover of all
pumps.
4. Remove gerotor assembly from gerotor cover or pump
housing.
5. Remove gerotor drive pin and drive coupling. Remove
gerotor cover locating pin from pump housing.
6. Inspect each part if they are to be reused. If either gerotor
assembly parts needs to be replaced, they must both be
replaced. Always replace O-rings and charge pump cover
gasket. Inspect journal bearing in gerotor cover for exces-
sive wear.
7. Lubricate gerotor assembly with clean hydraulic oil
before assembly.
8. Install gerotor drive pin into hole in drive coupling.
Apply grease or petroleum jelly to keep in place.
9. Install drive coupling on pump shaft with smaller out-
side diameter facing away from shaft.
10. Install gerotor assembly onto coupling.
11. Install gerotor cover locating pin into pump housing.
Install gerotor cover assembly over gerotor. Locating pin
must engage slot in gerotor cover.
NOTE: Charge pump rotation is determined by location of gerotor
recess and pressure balance hole in gerotor cover. Different
gerotor covers are used for clockwise and counterclockwise
rotation pumps.
12. Install new pressure balance O-rings to gerotor cover
and retain with petroleum jelly or grease.
13. Install charge pump cover locating pins and new charge
pump cover gasket.
14. Install charge pump cover. Cover must engage gerotor
cover and locating pins. Install charge pump cover
screws. Torque evenly to 26 - 32 ft-lb (36-43 Nm).
15. Reinstall auxiliary pump if necessary.
Figure 5-75. Charge Pump Components
1. Cover Retaining Screw 6. Gerotor Cover Locating Pin
2. O-Ring 7. Charge Pump Cover
Locating Pin
3. Gerotor Cover
4. Gerotor Assembly 8. Gerotor Drive Pin
5. Drive Coupling 9. Gasket