JLG 660SJ Service Manual - Manual (Page 173)

SECTION 5 - HYDRAULICS
3120840 – JLG Lift – 5-41
3. Remove the control sleeve from the pump.
4. Remove the control inlet screen plug from the inlet
passage next to the control sleeve bore, using an
internal hex wrench (5/32”).
5. The control orifice plugs are located in threaded
passages under the servo piston cover. Remove the
servo piston cover and gasket, and remove the ori-
fice plugs using an internal hex wrench (7/32”).
6. Replace the O-ring on the bottom of the control
housing.Lightly lubricate all O-rings with clean petro-
leum jelly prior to assembly. The control spool and
sleeve are a matched set and are not available sepa-
rately.
7. Reinstall the control orifice plugs into their passages
and replace the servo piston covers.