Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Руководство по обслуживанию

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BRAKES 5-19
CALIPER O V ER H A U L
C A U T IO N : Always use denatured alcohol or brake
flu id to clean any caliper parts. Never use mineral-
base cleaning solvents such as gasoline, kerosene,
carbon-tetrachloride, acetone, paint thinner or units
o f like nature as these solvents deteriorate rubber
parts, causing them to become soft and swollen in
an extrem ely short tim e.
Removal
1. D isconnect the hose fro m the steel brake line an d cap or
tape the fittings to p revent dirt from entering the line or
hoses.
2. Rem ove th e U -shaped retainer from the hose fitting.
3. W ithdraw th e hose from th e fram e support bracket and
rem ove th e caliper w ith th e hose attac h ed . Rem ove the
brake shoes from th e caliper.
Disassembly
1. Clean the ex terio r o f th e caliper using d en atu red alcohol
or equivalent and place on a clean w ork surface.
2. Rem ove th e brake hose fro m the caliper and discard the
copper gasket. C heck th e hose for w orn spots, cracks or
o th e r signs o f d e terio ratio n . D iscard th e hose, if dam ­
aged, and replace w ith a new hose.
3. D rain th e brake fluid from the caliper.
W A R N IN G : DO N O T P LA C E T H E F IN G E R S IN
F R O N T O F T H E P IS T O N IN A N A T T E M P T TO
C A T C H O R P R O T E C T IT W H E N A P P L Y IN G
C O M P R E S S E D A IR .
4. Using clean shop tow els, pad the in te rio r o f the caliper
and rem ove the p isto n by directing com pressed air in to
the caliper inlet hole (Fig. 37).
Fig. 3 7 —R e m o v in g P iston F ro m C aliper
C A U T IO N : Use just enough air pressure to ease
the piston o ut o f the bore. Do n ot blow piston out
o f the bore.
N O T E : A n o ther method o f removing the piston is
to stroke the brake pedal (gently) w hile the h y­
draulic lines are still connected. This w ill push the
piston o ut o f the caliper bore.
5. Using a screw driver and caution so as n o t to scratch the
piston bo re, pry th e dust b o o t o u t o f the caliper piston
bore.
6
. Using a small piece o f w ood or plastic rem ove the piston
seal from its groove in the caliper piston bore.
C A U T IO N : Do n ot use a metal tool o f any kind
fo r this operation.
7. Remove the bleeder valve from the caliper.
Cleaning and Inspection
N O T E : The dust boot, piston seal, rubber bushings
and sleeves are to be replaced each tim e th at the
caliper is overhauled. Discard these parts — do not
bother to clean and inspect them .
1. Clean all parts (o th e r th a n those m en tio n ed above) in
d en atu red alcohol. Use dry, filtered, com pressed air to
dry parts and blow o u t all passages in the caliper and
bleeder valve.
C A U T IO N : The use o f lubricated shop air will
leave a film of mineral oil on the metal parts. This
may damage rubber parts when they come in con­
tact after reassembly.
2. Check the m o u n tin g bolts for corrosion or o th e r damage.
Do n o t a tte m p t to clean up th e bolts. I f th e y appear
co rro d ed — replace them .
3. C arefully exam ine the outside surface o f the piston for
scoring, nicks, corrosion an d w orn or dam aged chrom e
plating. I f any surface defects are d etected , replace the
piston.
C A U T IO N : The piston outside diam eter is the
primary sealing surface in the caliper assembly. It is
manufactured and plated to close tolerances. Re­
finishing by any means or the use o f any abrasive is
not an acceptable practice.
4. Check the bore in th e caliper for the same defects as the
piston. The piston bore, how ever, is not plated and stains
or m inor corrosion can be polished with crocus cloth.
C A U T IO N : Do not use emery cloth or any other
form o f abrasive. Thoroughly clean the caliper after
the use o f crocus cloth. If the bore cannot be
cleaned up in this manner, replace the caliper.
Reassembly
1. Lubricate the caliper piston bore and the new piston seal
C H E V Y V A N S H O P M A N U A L