Chevrolet 10 Series 1970 Service Manual page 247

F ig . 16—B le e d in g W h e e l C y lin d e r
4. If the main c y lin d e r has b le e d e r v a lv e s ,
lo o se end o f the b le e d e r hose o v e r the va lve . Have
a h elp er pump the brake pedal two o r three tim es
and hold p ressu re (ap p roxim ately 75 lb s .) on the
pedal.
5. Open b le e d e r va lv e approxim ately 3/4 of a turn using
a tool such as J-21472.
6. C lose the b le e d e r v a lv e just b efo re the end o f the
brake stroke.
7. Continue operating the
cylin d er when n ecessa ry, until brake fluid containing
no a ir bubbles e m e rg e s fro m
8. If the veh icle is equipped with a fra m e
b o o ster, the b oo ster should be bled a fte r the main
cylin d er. Use the sam e method as d escribed in
item s 4 thru 7.
9. The sequence of bleeding is to bleed the cylin d er
next in line (distance) fro m the main cylin d er until
a ll cylin d ers have been purged o f a ir.
NOTE:
On veh ic le s with upper and lo w e r wheel
cylin d ers on the sam e wheel always bleed the
lo w e r cylin d er fir s t.
10. F il l m ain cylin d er
F igu re 15 and in sta ll diaphragm and c o v e r.
CA U TIO N :
DO N O T M OVE THE V E H IC LE U N -
T I L A FIR M P E D A L IS O B T A IN E D .
slip the
pedal, r e fillin g the main
the b le e d er va lve.
mounted
r e s e r v o ir to le v e l shown in
PARKING BRAKE CABLE—LUBRICATION
Parkin g brake cables should be lu bricated during a
brake relin e job o r when adjusting brakes i f cables fe e ls
sticky. See Section 0 fo r lubrication.
When lu bricating the brake cables, the re a r brake
drums must be rem oved on 1/2 and 3/4 ton v e h ic le s in
o r d e r to make sure that lubricant is not fo rced into the
brake assem bly during lubrication.
BRAKE PEDAL A D J U S T M E N T -C A -K A -P A 1 0 - 2 0 -
CA-PA 3 0 -4 0 -5 0 C D -C G -M A 6 0 SERIES (Fig. 17)
NOTE:
A ll brake attachments a re im portant
attaching parts in that the could a ffect the p e r ­
form an ce o f v ita l components
and/or could resu lt in m ajor re p a ir expense.
They must be replaced with parts o f the same
p art numbers o r with equivalent p arts i f r e ­
placem ent becom es n ecessary. Do not use r e ­
placem ent parts o f le s s e r quality o r substitute
design. Torque values must be used as sp ecified
during rea ssem b ly to assure p ro p er retention o f
these parts.
1. Loosen locknut on adjustable push rod between the
brake pedal and main cylin der push rod.
2. To obtain c o r r e c t clearan ce between the push rod and
the main cy lin d er o r a ir brake control va lv e, adjust
the push rod so that the fr e e tra v e l m easured at the
cen ter o f the pedal is .06 to .25 range fo r standard
main cylin ders o r without fra m e mounted vacuum o r
a ir booster.
3. Tighten locknut on adjustable push rod and recheck
fr e e tra vel.
4. Adjust brake ligh t switch by pulling back on pedal
unit until contact is made with pedal stop. Stop lamps
should go on a fte r approxim ately .60 inches pedal
pad tra vel.
BRAKES 5-9
and system s,
CHEVROLET TRUCK SERVICE MANUAL