Chevrolet 10 Series 1970 Service Manual page 246

BRAKES 5-8
J-22489
F ig . 14—Brake B leeder A d a p te r Tool J -2 2 4 8 9 In s ta lle d as T y p ic a l
3. R eplace a ll rubber parts of the system , including
brake hoses.
4. R e fill the system .
5. B leed the system .
Pressure Bleeding
1. Clean all d irt fro m the top of the main cylin der and
rem ove the c o v e r and diaphragm.
2. Reduce fluid le v e l in the main cylin der to approxim a­
te ly one half full.
3. Install the appropriate b le ed e r adapter on the main
cylin d er (fig . 14). Connect the hose fro m bleed er
equipment to b le ed e r
va lve on the equipment.
NOTE:
Brake b leed er equipment should be ca­
pable of exertin g 30 to 50 lbs. hydraulic p ressu re
on the brake system .
4. Pou r a sufficient amount of brake fluid into a trans­
parent container to ensure that the end of a b leed er
hose w ill rem ain subm erged during bleeding. P la ce
one end of the b lee d er hose into the container,
(fig . 16)
adapter. Open the re le a se
F ig . 15—C o rre c t M a in C y lin d e r F lu id Level
5. If the main cylin d er has b lee d er v a lve s,
loose end of the b le ed e r hose o v e r the va lve and
using a b lee d er wrench such as J-21472 open the
va lve 3/4 of a turn. When fluid flow s without bubbles,
close the va lve tightly.
6. The sequence o f bleeding is to bleed the cylin der
next in line (distance) from the main cylin d er until
a ll cylin ders have been purged of a ir.
7. If the veh icle is equipped with a fram e
booster the b o oster should be bled a fter the main
cylinder.
NOTE:
On ve h ic le s with upper and lo w e r wheel
cylin d ers on the same wheel always bleed the
lo w e r cylin der firs t.
8. A fte r the entire system has been purged of a ir, close
the va lve on the b leed er equipment and rem ove the
b leed er adapter.
NOTE:
When rem oving the b le ed er equipment,
place a clean cloth below the main cylin d er to
absorb any fluid spillage as the adapter is r e ­
m oved. W ipe a ll areas dry if fluid was spilled
as brake fluid w ill cause paint distortion.
9. F ill main cylin d er r e s e r v o ir as shown in F igu re 15.
10. Install main cylin d er diaphragm and co v e r.
CA U TIO N :
DO N O T MOVE THE V E H IC L E UN­
T IL A F IR M P E D A L IS O B T A IN E D .
M an u al Bleeding
Manual bleeding is s im ila r to p ressu re bleeding except
that the brake fluid is fo rce d through the lin es by pump­
ing the brake pedal.
1. Clean a ll d irt fro m the main cylin d er and rem ove the
c o ve r and diaphragm.
2. F ill the main cylin d er
co ve r.
3. Pour a sufficient amount of brake fluid into a tran s­
parent container to ensure that the end of a b leed er
hose w ill rem ain subm erged during bleeding. Place
one end o f the hose into the container (fig . 16).
slip the
mounted
r e s e r v o ir and replace the
CHEVROLET TRUCK SERVICE MANUAL