expel all the trapped air. Be sure to monitor the fluid
level in the pressure bleeder. It must stay at the
proper level so air will not be allowed to reenter the
brake system through the master cylinder.
(6) Replace all 4 bleeder screw rubber dust caps.
BLEEDING WITHOUT A PRESSURE BLEEDER
If a pressure bleeder is not available. A good brake
fluid flow can be obtained by manual bleeding of the
brake hydraulic system, following these steps.
(1) Remove rubber duct caps from all 4 bleeder
screws.
(2) Attach a clear hose to the bleeder screw at one
wheel and feed the hose into a clear jar containing
fresh brake fluid (Fig. 29).
(3) Pump the brake pedal three or four times and
hold it down before the bleeder screw is opened.
(4) Then, while the pedal is being held down, open
the bleeder screw at least 1 full turn. When the
bleeder screw opens the brake pedal will drop all the
way to the floor.
(5) Release the brake pedal only after the bleeder
screw is closed.
(6) Repeat steps 1 through 5, four or five times at
each bleeder screw. This should pass a sufficient
amount of fluid to expel all the trapped air from the
brakes hydraulic system. Be sure to monitor brake
fluid level in master cylinder fluid reservoir, to
ensure it stays at a proper level. This will ensure air
does not reenter brake hydraulic system through
master cylinder.
(7) Only after a short stroke and solid brake pedal
feel is obtained, test drive vehicle to ensure brakes
are operating correctly.
(8) Replace all 4 bleeder screw dust caps.
MASTER CYLINDER BLEEDING
CAUTION: When clamping the master cylinder in a
vise for bleeding, carefully tighten the vise just
enough to hold the master cylinder from moving.
Excessive pressure can damage the master cylin-
der.
(1) Clamp the master cylinder in a vise (Fig. 30).
NOTE: The master cylinder on this vehicle uses
ISO style flares and metric threads on the master
cylinder outlet ports. Special Tool Packages 8129
and 8305 have ISO style flares and metric threads
on their bleeding tubes.
(2) Position the appropriate bleeding tools from
packages, Special Tool 8129 and 8305, on the master
cylinder. Place open ends in the fluid reservoir. Then,
attach the bleeding tube fittings to the master cylin-
der outlet ports. (Fig. 30)
NOTE: Make sure the open ends of the bleeding
tubes are below the surface of the brake fluid when
the reservoir is filled to the proper level.
(3) Fill reservoir with brake fluid conforming to
DOT 3 specifications such as Mopar or Equivalent.
(4) Using a wooden dowel per (Fig. 30). Depress
master cylinder pistons slowly, and then allow pis-
tons to return to released position. Repeat several
times until all air bubbles are expelled.
(5) Remove bleeding tubes from cylinder, plug out-
lets and install filler cap.
(6) Remove master cylinder from vise and install
on power brake vacuum booster.
NOTE: It is not necessary to bleed the entire
hydraulic system after replacing the master cylin-
der, providing that the master cylinder has been
bled and filled upon installation.
BRAKE TUBE REPAIR
All available brake systems on this vehicle use ISO
STYLE TUBING FLARES (Fig. 31) at all chassis
brake tube to component locations, Only the con-
nection between the rear proportioning valve
and flex hose uses a double inverted flare.
Only double wall 4.75mm (3/16 in.) steel tubing
should be used for replacement of the chassis brake
tubes. The chassis brake tubes used on this
vehicle are coated with a zinc alloy and alumi-
num rich coating referred to as Prokote 2000. If
a chassis brake tube requires replacement, only
Fig. 30 Bleeding Master Cylinder
1 – WOODEN DOWEL
2 – MASTER CYLINDER
3 – FLUID RESERVOIR
4 – SPECIAL TOOL 8129
5 – SPECIAL TOOL 8305
LH BRAKES 5 - 21
SERVICE PROCEDURES (Continued)
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