Chrysler Vehicle User Manual page 238

TJ
COMBINATION VALVE (Continued)
DIAGNOSIS AND TESTING - COMBINATION
VALVE
Pressure Differential Switch
(1) Have helper sit in drivers seat to apply brake
pedal and observe red brake warning light.
(2) Raise vehicle on hoist.
(3) Connect bleed hose to a rear wheel cylinder
and immerse hose end in container partially filled
with brake fluid.
(4) Have helper press and hold brake pedal to floor
and observe warning light.
(a) If warning light illuminates, switch is operat-
ing correctly.
(b) If light fails to illuminate, check circuit fuse,
bulb, and wiring. The parking brake switch can be
used to aid in identifying whether or not the brake
light bulb and fuse is functional. Repair or replace
parts as necessary and test differential pressure
switch operation again.
(5) If warning light still does not illuminate,
switch is faulty. Replace combination valve assembly,
bleed brake system and verify proper switch and
valve operation.
REMOVAL
(1) Remove brake lines that connect master cylin-
der to combination valve (Fig. 50) .
(2) Disconnect brake lines that connect combina-
tion valve to front and rear brakes.
(3) Disconnect wire from combination valve switch
terminal. Be careful when separating wire connector
as lock tabs are easily damaged if not fully disen-
gaged.
(4) Remove nuts attaching combination valve
bracket to booster studs and remove valve bracket off
booster studs (Fig. 51) .
INSTALLATION
(1) Position valve bracket on booster studs and
tighten bracket attaching nuts to 20 N·m (15 ft. lbs.).
(2) Align and start brake line fittings in combina-
tion valve and master cylinder by hand to avoid cross
threading.
(3) Tighten brake line fittings at combination valve
to 19 N·m (14 ft. lbs.).
Fig. 50 Combination Valve/Master Cylinder
1 - COMBINATION VALVE
2 - MASTER CYLINDER
Fig. 51 Combination Valve Bracket
1 - MASTER CYLINDER
2 - COMBINATION VALVE BRACKET
(4) Tighten brake line fittings at master cylinder
to 19 N·m (14 ft. lbs.).
(5) Connect wire to differential pressure switch in
combination valve.
(6) Bleed base brake system. (Refer to 5 - BRAKES
- STANDARD PROCEDURE).
BRAKES - BASE 5 - 29