Chevrolet BEAUVILLE SPORTVAN G10 SERIES, Руководство по обслуживанию

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BRAKES 5-22
ham m er. With a box-end or socket w rench, th read a
#6
- 3 2 x 5 /8 ” long self-tapping screw in to the
tu be-fitting in sert. Using the claw end o f the h am ­
m er, remove th e screw and insert.
4. Rem ove th e casting from th e vise and inspect the bore
for corrosion, pits an d foreign m a tte r. Be sure the o u tle t
po rts are clean. In sp ec t the fluid reservoirs for foreign
m a tte r. Check th e bypass an d com pensating ports to the
m a s t e r c y lin d e r bore to determ ine if they are
u n restricted .
5. Rem ove th e prim ary seal, prim ary seal p ro te c to r and
secondary seals fro m the secondary piston.
Cleaning
Use d en atu red alcohol or clean brake fluid to thoroughly
clean all reusable brake parts. Im m erse in the cleaning fluid
and b rush m etal parts w ith hair brush to rem ove foreign
m a tte r. Blow o u t all passages, orifices and valve holes. Air dry
and place cleaned parts on clean paper or lint free clean cloth.
I f slight rust is fo u n d inside either th e fro n t o r rear half
housing assem blies, polish clean w ith crocus clo th or fine
em ery paper, w ashing clean afterw ards.
C A U T IO N : Be sure to keep parts clean until reas­
sembly. Re-wash at reassembly if there is any
occasion to doubt cleanliness — such as parts
dropped or left exposed fo r eight hours or longer.
If there is any suspicion o f contam ination or any
evidence o f corrosion, com pletely flush the car
hydraulic brake system in accordance w ith this shop
manual. Failure to clean th e hydraulic brake system
can result in early repetition of trouble. Use o f
gasoline, kerosene, anti-freeze, alcohol or any other
cleaner, w ith even a trace o f mineral o il, will damage
rubber parts.
Rubber Parts
Wipe fluid fro m the ru b b er p arts and carefully inspect each
rubber p a rt for cuts, nicks or o th e r damage. These parts are
the key to the co n tro l o f fluid flow. I f the u n it is in for
overhaul, or if there is
any
question as to the serviceability o f
rubber parts, REPLACE them!
Badly dam aged item s, or those w hich w ould take extensive
w ork or tim e to repair, should be replaced. In case o f d o u b t,
install new parts. Do n o t rely on th e brake u n it being
overhauled at an early or p ro p er interval. New parts will
provide m ore satisfactory service, even if the brake u n it is
allow ed to go b ey o n d th e desired overhaul period.
Assembly
I f th e brass tube inserts were rem oved, place the m aster
cylinder in a vise so th a t the o u tle t holes are u p . P osition the
new brass tu b e inserts in th e o u tle t holes, m aking sure th e y are
n o t cocked. The recom m ended m e th o d o f seating these inserts
is to th rea d a spare brake line tube n u t in to each o u tle t hole
and tu rn th e n u ts dow n until the insert b o tto m s.
(Remove the
tube n ut and check the outlet hole fo r loose brass burrs, which
might have been turned up when the insert was pressed into
position.)
Each vehicle application o f these cylinders is designed to
p roduce th e correct displacem ent o f fluid from b o th the fro n t
and rear cham bers u n d er norm al, failed and partially failed
conditions. C ylinders are designed so th a t this variable dis­
placem ent requirem ent is co n tro lled w ithin each bore size by
the secondary piston.
Because the pistons vary in length, it is necessary to m ark
th em w ith id entification rings. It is im perative th a t exact
replacem ents be m ade w hen servicing the m aster cylinders.
W ith all o f the variables to be fo u n d in m aster cylinders,
w hich look similar externally, it is im p o rta n t th a t the com ­
plete assemblies be properly identified. F o r this purpose a
tw o-letter m etal stam p will be fo u n d on the en d o f each
m aster cylinder. This tw o -letter stam p indicates th e displace­
m ent capabilities o f a particular m aster cylinder. It is, th e re­
fore, m an d ato ry th a t w hen m aster cylinders are replaced, they
are replaced w ith cylinders bearing the same tw o-letter stam p.
1. Place new secondary seals in the tw o grooves in the flat
end o f the secondary piston assembly. The seal w hich is
nearest th e flat en d will have its lips facing tow ard this
flat end. On D elco u nits, the seal in the second groove
should have its lips facing tow ard th e end o f the sec­
o ndary piston w hich contains the small com pensating
holes. On Bendix u n its, the seal in th e second groove is
an “ O ” ring seal.
2. Assemble a new prim ary seal and prim ary seal p ro tec to r
over the en d o f the secondary piston opposite the
secondary seals, so th a t th e flat side o f th e seal seats
against the flange o f the piston w hich contains the small
com pensating holes.
3. In order to insure correct assem bly o f the prim ary piston
assem bly, a com plete prim ary piston assem bly is included
in the repair kits.
4. C oat the bore o f the m aster cylinder w ith clean brake
fluid. C oat the prim ary and secondary seals o n the
secondary piston w ith clean brake fluid. Insert the
secondary piston spring retainer in to the secondary
piston spring. Place the retainer and spring dow n over the
end o f th e secondary piston so th a t th e reta in er locates
inside the lips o f the prim ary seal.
5. H olding the m aster cylinder w ith the open end o f the
bore up or dow n, push the secondary p isto n in to the
bore so th a t the spring will seat in against th e closed end
o f the bo re. Use a small w ooden rod to push the
secondary piston to seat.
6
. Place the m aster cylinder in a vise w ith the o pen end o f
bore up. C oat the prim ary an d secondary seals on the
prim ary p isto n w ith clean brake fluid. Push the prim ary
p isto n , secondary piston sto p first, in to th e bore o f the
m aster cylinder. H old the p isto n dow n and snap the lock
ring in to position in the small groove in the I.D. o f the
bore.
C A U T IO N : Do not tighten vise too tig h tly as
damage to the master cylinder could result.
7. C ontinue to hold the prim ary piston dow n. This will also
m ove the secondary piston forw ard and will insure th a t
the secondary piston will be forw ard far enough to clear
the stop screw hole, w hich is in th e b o tto m o f the fro n t
fluid reservoir. The stop screw is now p o sitioned in its
hole and tigh ten ed to a torque o f 33 in. lbs.
C H E V Y V A N S H O P M A N U A L