Gast will NOT guarantee field-rebuilt product
performance. For performance guarantee, the product
must be returned to a Gast Authorized Service Facility.
Service Kit contents vary. Most contain gasket and filter
parts.
SERVICE KIT INSTALLATION
c
Disconnect electrical power supply cord before
installing Service Kit.
If product is hard wired into system, disconnect
electrical power at the circuit breaker or fuse box
before installing Service Kit.
Vent all air lines to release pressure or vacuum.
Failure to follow these instructions can result in
death, fire or electrical shock.
WARNING
Electrical Shock Hazard
7. Clean head and valve plate using water-based
solvents.
8. Reattach exhaust valve and valve retainer to valve
plate. Note location of “X” stamped on valve retainer.
This must be orientated as shown or valve may break
prematurely.
9. Torque pan head screw to 12 in.-lbs. (once assembled,
make sure valve remains over exhaust port when
closed).
10. Reinstall gasket and valve plate into head. Valve plate
and head are designed so that valve plate can be
installed in one orientation only.
11. Install four flat head screws and torque to 12 in-lbs.
12. Reinstall intake valve and its retainer. Note location of
“X” stamped on valve retainer. This must be orientated
as shown or valve may break prematurely.
13. Reinstall pan head screw and torque to 12 in-lbs.
14. Tighten head in place using four head screws and
torque to 25-27 in-lbs.
Check that all external accessories such as relief valves
and gauges are not damaged before
re-operating product.
If pump still does not produce proper vacuum or pressure,
send unit to a Gast Authorized Service Facility for repair.
Follow these steps to replace diaphragm:
1. Label ports noting direction of arrows so you can orient
pump head correctly during reinstallation.
2. Remove four corner head screws.
3. Remove head assembly.
NOTE:Head assembly is inseparable. Do not attempt to
disassemble.
4. Remove four flat head screws on retainer plate.
5. Remove retainer plate and diaphragm.
6. Clean pump head and retainer using water base solvents.
NOTE:
Do not use petroleum-base compounds, acids, caustics,
or chlorinated solvents to clean or lubricate any parts, It
will reduce service life of pump.
7. Re-attach retainer plate and diaphragm to rod with four flat
head screws. Torque screw to 20 in-lbs.
8. Make certain diaphragm is in recessed area of bracket and
re-install head assembly in proper orientation, twisting it
slightly back and forth to seat diaphragm in head and bracket.
9. Tighten head in place using four head screws and torque to
25-27 in-lbs.
Valve Replacement
Follow these steps to replace valves:
1. Label ports noting direction of arrows so you can orient
pump head correctly during reinstallation.
2. Remove four corner head screws.
3. Remove head assembly.
4. Remove valve plate by removing four flathead screws
around perimeter and pan head screw in center (this screw
also retains intake valve).
5. Remove intake valve, its retainer, valve plate and gasket.
6. Remove pan head screw from other side of valve plate (this
screw retains exhaust valve).
