Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Руководство по обслуживанию

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BRAKES 5-14
Wheel Cylinder Repair
Wheel cylinders should n o t be disassem bled unless they are
leaking or unless new cups and b o o ts are to be installed. I t is
n o t necessary to rem ove th e brake cylinder from the backing
plate to disassem ble, inspect, and overhaul th e cylinder.
Removal is necessary only w hen th e cylinder is dam aged or
scored b eyond repair.
Removal
1. Place vehicle on a hoist.
2. Rem ove wheel an d tire assem bly. Back o ff brake ad ju st­
m en t, if necessary, and rem ove drum .
3. D isconnect brake system hydraulic line from cylinder.
4. Rem ove brake shoe pull back springs.
5. Rem ove screws securing w heel cylinder to flange plate.
Disengage cylinder push rods from brake shoes and
remove cylinder.
Disassembly (Fig. 28)
1. Rem ove b o o ts from cylinder ends.
2. Rem ove pistons an d cups.
Inspection and Cleaning
N O T E : Staining is not to be confused w ith cor­
rosion. Corrosion can be identified w ith pits or
excessive bore roughness.
1. Inspect cylinder b o re, C heck for staining and corrosion.
D iscard cylinder if corroded.
2. Polish any discolored or stained area w ith crocus clo th by
revolving th e cylinder on th e cloth su p p o rted by a finger.
Do n o t slide the cloth in a lengthw ise m anner under
pressure.
C A U T IO N : Before washing parts, hands must be
clean. Do not wash hands in gasoline or oil before
cleaning parts. Use soap and water to clean hands.
Fig. 2 8 —Wheel C ylin der—Explode
3. Wash the cylinder and m etal parts in d enatured alcohol.
4. Rem ove excess cleaning fluid from the cylinder. Do n o t
use a rag to dry the cylinder as lin t from th e rag cannot
be k e p t from th e cylinder bore surfaces.
5. Check piston for scratches o r o th e r visual dam age; re­
place if necessary.
Assembly
1. L ubricate the cylinder bore w ith clean brake fluid and
insert spring-expander assem bly.
2. Install new cups w ith flat surface to w ard o u te r ends o f
cylinder. Be sure cups are lint and dirt free before
insertion. Do n o t lubricate cups prior to assembly.
3. Install new pistons in to cylinder w ith flat surfaces tow ard
c en ter o f cylinder. Do not lubricate pistons before
installation.
4. Press new b o o ts o n to cylinder by h and. Do n o t lubricate
b oots prior to installation.
Installation
1. P osition wheel cylinder to brake flange p la te. Install
screws and tighten securely.
C A U T IO N : See "C a u tio n " on Page 1 o f this
section.
2. Install all push rods and pull back springs.
3. C onnect hose or line to wheel cylinder.
C A U T IO N : See "C a u tio n " on Page 1 o f this
section.
4. Install all parts rem oved for accessibility.
5. Bleed hydraulic system as o u tlined in this section.
6 . C heck brake pedal o p eration and rem ove vehicle from
hoist.
BRAKE DRUMS
A lanced “ k n o ck o u t” area is provided in the web o f the
brake drum or backing plate for servicing purposes in the event
retracting o f th e brake shoes is required in order to rem ove the
drum .
A small screwdriver or h o o k ed wire m ay be inserted to
disengage the autom atic adjuster actuating lever so the star
w heel m ay be tu rn e d (Fig. 22).
Inspection and Reconditioning
Whenever brake drum s are rem oved, they should be
thoroughly cleaned and inspected for cracks, scores, deep
grooves and out-of-round. A ny o f these co nditions m ust be
co rrected since they can im pair the efficiency o f brake
o peration and cause prem ature failure o f o th e r parts.
W A R N IN G : A cracked drum is unsafe fo r fu rth er
service and must be replaced. Do n o t atte m p t to
weld a cracked drum.
PUSH R O D A N D B O O T
P IS T O N
C UP RETURN S P R IN G W IT H E X P A N D I
W H E E L C Y LIN D E R H O U S IN G
P IS T O N CUP
P IS TO N
P IS T O N CUP
BLEEDER S C R E W
PUSH R O D A N D B O O T
C H E V Y V A N S H O P M A N U A L