Chrysler Concorde 1993 Service Manual page 118

5 - 24 BRAKES
Each rear brake circuit has its own screw-in propor-
tioning valve which is attached to the rear brake outlet
ports of the hydraulic control unit (HCU). The valves
limit brake pressure to rear brakes after a certain
pressure is reached. This improves front to rear brake
balance during normal braking.
Fig. 3 ABS PROPORTIONING VALVE
IDENTIFICATION
Screw in proportioning valves can be identified by
the numbers stamped on the body of the valve. The
first digit represents the slope, the second digit repre-
sents the split (cut-in) point, and the arrow represents
the flow direction of the valve. Be sure that the
numbers listed on the replacement valve are the
same as on the valve that is being removed. See
(Fig. 3) for detail of the valve identification.
NON-ABS AND ABS PROPORTIONING VALVE APPLICATIONS
HYDRAULIC SYSTEM SERVICE PROCEDURES
BRAKE WARNING SYSTEM
CHECKING BRAKE WARNING SWITCH UNIT
The Red Brake Warning light will come on when
the parking brake is applied with the ignition key
turned ON. The same light will also illuminate
should one of the two service brake hydraulic sys-
tems fail.
PROPORTIONING VALVES
TESTING PROPORTIONING VALVE UNIT
If premature rear wheel skid occurs on hard brake
application, it could be an indication that a malfunc-
tion has occurred with the proportioning valve unit.
The proportioning valve is designed with two sep-
arate systems. One half controls the right rear
brake, and the other half controls the left rear brake.
Therefore, a road test to determine which rear brake
slides first is essential.
RIGHT REAR WHEEL SLIDES FIRST
CAUTION: All brake line fittings used on the L.H.
platform vehicle use ISO style tubing flares. Ensure
that when fabricating adapter tubes required to test
proportioning valve operation. That only ISO style
tubing flares are used at proportioning valve con-
nections. Failure to use ISO style tubing flares at
the proportioning valve connections, will destroy
tubing seats in proportioning valve.