JLG 510AJ Service Manual - Manual (Page 271)

SECTION 5 - HYDRAULICS AND HYDRAULIC SCHEMATICS
3121181 – JLG Lift – 5-51
Charge Pump
NOTE: Charge pump may be disassembled to inspect and clean,
or to change the auxiliary shaft drive coupling.
1. Remove auxiliary pump, if necessary.
2. Remove screws retaining charge pump cover to pump
housing. Seven Torx T45 screws are used with the "no
pad" or SAE "A" auxiliary mounting pad charge pump
cover Six screws are used with the SAE "B" auxiliary
mounting pad charge pump cover. Remove charge
pump cover, gasket, and cover locating pins.
3. Remove gerotor cover assembly from charge pump
cover or back of pump housing. Remove two gerotor
cover O-rings.
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. Each part should be inspected separately if they are to
be reused. If either of the 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 excessive wear.
7. Prior to assembly, lubricate gerotor assembly with clean
hydraulic oil.
8. Install gerotor drive pin into hole in drive coupling, and
retain with grease or petroleum jelly.
9. Install drive coupling on pump shaft with smaller out-
side diameter oriented away from pump shaft. Different
couplings are used with different auxiliary pad options.
10. Install gerotor assembly on coupling.
11. Install gerotor cover locating pin in pump housing.
Install gerotor cover assembly over gerotor. The 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 onto the gerotor
cover and retain with petroleum jelly or grease. (An
additional O-ring was used on the gerotor cover of very
early production pumps with the SAE "A" pad option.)
13. Install the charge pump cover locating pins and a new
charge pump cover gasket.
14. Install charge pump cover. The cover must engage the
gerotor cover and locating pins. Install charge pump
cover screws. Torque evenly to 26-32 ft-lb (36-43 Nm).
15. If necessary, reinstall auxiliary pump.
1
2
3
4
5
6
9
7
7
8
1. Cover Retaining Screw
2. O-ring
3. Geroter Cover
4. Geroter Assembly
5. Drive Coupling
6. Geroter Cover Locating Pin
7. Charge Pump Cover Locating Pin
8. Geroter Drive Pin
9. Gasket
Figure 5-88. Charge Pump Components