Pontiac tempest 1968 Service Manual page 115

4-12
1968 P O N T I A C SERVICE MANUAL
2. Insert new expansion plug retainer and tap in
until it bottoms (Fig. 4-20).
ASSEMBLY OF FIRST STAGE HOUSING AND
VALVE MECHANISM
1. If removed, position bushings in first stage
housing and install rocker arm and swivel arm. Align
holes in rocker and swivel arms and install retaining
pin, small end first.
NOTE: If distributor mechanism failed to operate
properly or one or more parts were found defec­
tive, use new parts in Distributor Valve and Arm
Package during remaining reassembly.
2. Install washer on intake valve and install in
first stage housing with intake valve retaining spring.
3. Install longer foot of valve tension spring in
boss on first stage housing, being careful not to dis­
tort spring (Fig. 4-21).
4. Position distributor valve so that short foot of
tension spring fits under valve and vertical leg is in
slot (Fig. 4-22).
5. Install distributor valve bushing, washer, dis­
tributor arm assembly, washer and secure with
screw (Fig. 4-23). Tighten screw to 12 lb. in.
6. Install two distributor valve stop bushings and
two arm assembly stop bushings.
NOTE: Do not install actuating arm, arm tension
spring or arm pivot screw at this time as rocker
arm must be free to permit entrance of piston into
first stage housing.
ASSEMBLY OF PISTON-DIAPHRAGM ASSEMBLY
1. Install new corprene washer, old plate (unless
damaged), new diaphragm (with outer lip toward
second stage of piston) and second plate (Fig. 4-24).
2. Using a 13/16" deep socket as a retainer in­
staller, press against the piston shoulder on the
first stage housing side with wood blocks to seat
retainer. The wood blocks used in the illustration
are each 3/4" x 3/4" x 12".
NOTE: Be sure retainer is securely seated in
order to affect an air tight seal against the cor­
prene seal.
3. Install new O-rings by rolling into groove.
Relieve any resulting twist.
4. Install new seals, using a piece of .020" shim
stock (Fig. 4-25).
CAUTION: Make sure shim stock has no sharp
edges that may cut seal. Do not stretch seal more
than is necessary to install. Seals must be in­
stalled so they are not twisted.
ASSEMBLY OF MAJOR COMPONENTS
1. Slide piston assembly straight into first stage
(large diameter) housing.