Chevrolet 70 1969 Series, Руководство по ремонту

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POWER BRAKE 5-8
Figure 3 — S t a n d a r d S to p m a ste r C h a m b e r C o m p o n e n ts
2. Pull out push rod and clam p it at the non-pressure
plate, using a vise or vise-grip pliers. This will relieve
tension of spring on diaphragm and clam p ring.
3. Remove clam p ring bolts. Spread clam p ring and re­
move from plates, then remove pressure plate and di­
aphragm .
4. Rem ove yoke and lock nut from push rod, then re­
move push rod and push rod spring (and spring re­
tainer on M idland-R oss cham bers).
CLEANING AND INSPECTION
1. Clean all m etal parts thoroughly, using a suitable
cleaning fluid.
2. Install new diaphragm , or any other rubber parts, if
worn or deteriorated. W hen a diaphragm is replaced,
the diaphragm in the corresponding brake cham ber
on the sam e axle should also be replaced.
3. Inspect push rod for bent or distorted condition and
replace with new part if necessary.
4. Exam ine push rod spring an d replace if weak or
broken. W hen replacing spring, be sure new spring
has the sam e tension as the spring in the brake cham ­
ber on the opposite wheel, otherwise unbalanced b rak ­
ing m ay result. If tension is not equal, replace both
springs.
5. Replace pressure plate or non-pressure plate if dis­
torted or if any dam age is evident at the clamping
flange.
ASSEMBLY (Fig. 2)
1. Rest push rod upright on a flat surface. On M idland-
Ross cham bers, install spring retainer on push rod.
Install push rod spring over push rod. Install non­
pressure plate on push rod and press down, com press­
ing spring, until it rests on the flat surface. Install vise
grip pliers or sim ilar tool on push rod at non-pressure
plate to hold spring compressed.
2. Place clam p ring over clam ping flange of the non-
pressure plate, aligning m ark s m ade prior to disas­
sembly.
3. Position diaphragm in pressure plate. Place pressure
plate and diaphragm on the non-pressure plate, w ork­
ing the clam p ring over the diaphragm bead and
clam ping flange of the pressure plate. M arks on pres­
sure plate, clam p ring, and non-pressure plate m ust be
aligned.
4. Using vise-grip pliers or C -clam p on lugs on clam p
ring, draw clam p ring together and install clam p bolts
and nuts. Tighten clam p ring bolts just enough to
form an airtight seal.
5. R em ove vise-grip pliers from push rod. Install lock
nut and yoke on push rod.
STANDARD STOPMASTER
BRAKE CHAM BERS
DISASSEMBLY (Fig. 3)
1. Scribe a m ark across the pressure housing, clam ping
ring, and the non-pressure housing to assure proper
assembly.
2. R em ove bolt and nut which secure clam ping ring.
3. Separate pressure housing from non-pressure housing.
4. Rem ove diaphragm , rod, boot and guide from hous­
ings.
CLEANING AND INSPECTION
1. Clean all m etal parts thoroughly, using a suitable
cleaning fluid. Blow dry with air or wipe dry with
cloth. (Do not use solvent on diaphargm .)
2. Exam ine diaphargm and replace with new part if any
signs of wear or deterioration are evident.
3. Inspect pressure housing for scratches, scores, or ex­
cessive wear. Exam ine all parts for obstructions and
remove any foreign m atter.
4. Exam ine diaphragm plate rod boot for deterioration
or cracks. If deterioration or other dam age is evident,
replace. In order to replace boot it is necessary to re­
move the plastic guide from the end of the rod. If the
guide is dam aged or worn, it too should be replaced.
Apply a liberal am ount of rubber cem ent to boot
flange and m ating surface on non-pressure housing.
CHEVROLET SERIES 70-80 HEAVY DUTY TRUCK SHO P M A N UA L