Impco HHI, Service Manual

Page: 469 / 485

469
NOTE
Be sure to identify the type of screw and its loca-
tion during each stage of disassembly to ensure
proper placement during reassembly.
7. Gently pull the Regulator away from the Ac-
tuator. If necessary, tap around the edge of
the face plate with the handle of a plastic
screwdriver to break the regulator free. Note
that the lever from the primary valve slides
into a slot of the secondary diaphragm, re-
quiring the Regulator to be moved sideways
to free the tab from the diaphragm. Remove
and discard Clamp Plate Seal.
The two major components of the EPR As-
sembly: Regulator and the Actuator.
Care must be used when removing regula-
tor from the actuator to prevent damage to
the lever and diaphragm. Neither part is
serviceable and if damaged, the entire
EPR assembly must be replaced.
8. Place Regulator face down and remove the
retaining screw holding the secondary lever.
9. Remove secondary lever, fulcrum pin and
spring.
10. Inspect lever and fulcrum pin for excessive
wear. If the pin diameter is reduced at any
point or if the holes in the lever are irregular
(oblong), the EPR assembly is not repairable
and must be replaced.
11. Turn the Regulator over and remove the
seven screws from the face of the Regulator.
Remove cover.
12. Remove the primary diaphragm.
13. Remove the body cover plate and C-clip
from the primary valve pin.
14. Turn the plate over and remove pin and
spring. Discard pin and keep the spring.
15. Remove the secondary body gasket.
16. Inspect the Regulator body and cover plates
for debris, deposits or “heavy ends” and re-
move using a Safety Solvent as necessary.
Ensure all mating surfaces are clean.
Optional:
If leaks are detected or if the replacement of the
O-rings on the Coolant Hose(s), Fuel Tempera-
ture Sensor or the Fuel Vapor Hose is deemed
necessary, the follow the additional steps. Oth-
erwise, continue to Reassembly.
17. Release coolant pressure.
18. Clamp off the two radiator hoses near the
point where they connect to the EPR.
19. Remove Coolant Hoses, Fuel Temperature
Sensor and Fuel Vapor Hose by first remov-
ing Retaining Clips, then pulling each out of
the EPR ports.
20. Remove O-rings from the Temperature Sen-
sor, both Coolant Hose fittings, and the Fuel
Vapor Hose. Clean Temperature Sensor
EPR ports and hose fittings as necessary us-
ing a Safety Solvent.
Use only Safety Solvents for the cleaning
of the regulator and its components. Sol-
vents such as carburetor or brake cleaners
may damage gaskets, seals, O-rings, di-
aphragms or other non-metal components.
REASSEMBLY OF EPR
1. Inspect all parts to ensure the Repair Kit is
complete and all components are free of de-
terioration, cracks, tears, etc.
2. Place the new primary valve pin into the
cover plate orifice.
3. Holding the valve pin in place, turn the body
cover plate over. Place the valve pin spring