Sounds like air in the ABS pump. There is a special way to bleed ABS Jeeps.
BRAKE BLEEDING (WITH ABS BRAKES)
ABS system bleeding requires conventional bleeding
methods plus use of the DRB scan tool. The procedure
involves performing a conventional bleed,
followed by use of the scan tool to cycle and bleed the
HCU pump and solenoids. A second conventional
bleed procedure is then required remove any air remaining
in the system.
(1) If a new master cylinder is to be installed,
bleed cylinder on bench before installing it in vehicle.
Refer to procedure in section covering master cylinder
service.
(2) Wipe master cylinder reservoir and cap clean
before removing cap. This avoids having dirt fall into
fluid. Then fill reservoir with Mopar brake fluid.
(3) Perform conventional brake bleed as described
in steps (4) and (5).
(4) Bleed master cylinder and combination valve at
brakeline fittings. Have helper depress and release
brake pedal while bleeding cylinder and valve.
(5) Bleed wheel brakes in recommended sequence
which is: right rear; left rear; right front; left front.
Bleed procedure is as follows:
(a) Attach bleed hose to caliper bleed screw. Immerse
end of hose in glass container partially filled
with brake fluid. Be sure hose end is submerged in
fluid (Fig. 3).
(b) Have helper depress and hold brake pedal to
floorpan.
(c) Open bleed screw 1/2 turn. Close bleed screw
when brake pedal contacts floorpan. Do not pump
brake pedal at any time while bleeding. This
compresses air into small bubbles which are
distributed throughout system. Additional
bleeding operations will then be necessary to
remove all trapped air from the system.
(d) Repeat bleeding operation at each wheel
brake unit fluid entering glass container is free of
air bubbles. Check reservoir fluid level frequently
and add fluid if necessary.
(6) Perform HCU bleed procedure with DRB scan
tool as follows:
(a) Connect scan tool to ABS diagnostic connector.
Connector is under carpet at front of console,
just under instrument panel center bezel.
(b) Select CHASSIS SYSTEM, followed by
TEVES ABS BRAKES, then BLEED BRAKES.
When scan tool displays TEST COMPLETE, dis-
Fig. 3 Typical Bleed Hose And Fluid Container
J BRAKE FLUID—BRAKE BLEEDING—BRAKELINES AND HOSES 5 - 11
connect scan tool and proceed to next step.
(7) Repeat conventional bleed procedure described
in steps (4) and (5).
(
Top off master cylinder fluid level and verify
proper brake operation before moving vehicle.
Help, new brakes worse than old!!!
