1994 JEEP CHEROKEE brakes

CAUTION: The pedal travel sensor and booster
must form a matched set. The cap on the sensor
plunger and the color dot on the booster shell are
color coded for identification, and to ensure they
are used as matched sets. Be sure the color on the
sensor cap and booster shell are the same before
installation. Refer to the Sensor Replacement infor-
mation before installing a new or original sensor.
(4) If new pedal travel sensor is being installed in
original booster, compare color dot on booster shell with
color of cap on sensor (Fig. 10). If both are same color,
proceed with installation. However, if colorsdo not
match, select correct color cap from kit supplied with
new sensor and install it on end of sensor plunger.
(5) Install O-ring on pedal travel sensor.
(6) Install sensor retaining ring on booster flange.
Be sure retaining ring is firmly seated.
(7) Insert sensor into booster. Be sure sensor is
fully seated and engaged in retaining ring.
(8) Connect booster push rod to brake pedal.
(9) Attach vacuum hose to booster check valve.
(10) Install master cylinder on booster. Tighten
cylinder attaching nuts to 25-30 Nzm (220-267 in.
lbs.) torque.
(11) Connect brakelines to master cylinder.
(12) Install combination valve bracket bolt if re-
moved.
(13) Connect reservoir hoses to HCU pipes.
(14) Connect sensor wires.
(15) Bleed brakes. Refer to procedure in this section.
(16) Install air cleaner and hoses.
ACCELERATION SENSOR REMOVAL
(1) On XJ models, tilt rear seat assembly forward
for access to sensor (Fig. 11).
(2) On YJ models, move driver seat forward or
rearward for access to sensor and mounting bracket
(Fig. 11).
(3) Disconnect sensor harness (Fig. 10).
(4) On XJ models, remove screws attaching sensor
to bracket. Then remove sensor.
(5) On YJ models, remove screws attaching sensor
bracket to floorpan. Then remove sensor from bracket.
ACCELERATION SENSOR INSTALLATION
(1) Note position of locating arrow on sensor. Sen-
sor must be positioned so arrow faces forward.
CAUTION: The sensor mercury switch will not func-
tion properly if the sensor is mispositioned. Verify
that the sensor locating arrow is pointing to the
front of the vehicle.
(2) Position sensor in mounting bracket (Fig. 10).
(3) Install and tighten sensor attaching screws to
2-4 Nzm (17-32 in. lbs.) torque.
(4) Connect harness to sensor. Be sure harness
connecter is firmly seated.
(5) Move seat back to normal position.
Fig. 10 Booster Push Rod And Pedal Travel Sensor
Fig. 11 Acceleration Sensor Mounting
5 - 52 ABS COMPONENT SERVICEJ

(5) Mark or tag HCU hydraulic lines for assembly
reference.
(6) Disconnect hydraulic lines at HCU.
(7) Move HCU harness and air cleaner hose pipe
aside for access to HCU bracket nuts.
(8) Remove single bolt and two nuts attaching
HCU to mounting bracket on inner fender panel
(Figs. 16 and 17).
(9) Remove HCU. Lift HCU up and off mounting
bracket studs. Then work HCU past brakelines and
master cylinder to remove it.
HCU INSTALLATIONÐXJ
(1) Connect master cylinder reservoir hoses to
HCU pipes.
(2) Position HCU assembly on mounting bracket
and install attaching nuts.(3) Connect hydraulic lines to HCU (Fig. 18). Line
fitting nuts and bosses on valve body ports are color
coded. Be sure lines are properly connected.
(4) Connect HCU harness wires to HCU.
(5) Check routing of HCU lines/hoses. Be sure
lines are not kinked and are clear of engine compo-
nents.
(6) Fill master cylinder reservoir with Mopar DOT
3 brake fluid or equivalent.
(7) Bleed brake system.
(8) Install air cleaner and hoses. Secure air cleaner
hose pipe to fender apron with clamp.
(9) Check brake pedal action. Bleed brakes again if
pedal is not firm (feels soft/spongy).
HCU REMOVALÐYJ
(1) Place shop towels or small container under
master cylinder reservoir hoses.
(2) Disconnect master cylinder reservoir hoses at
HCU.
(3) Disconnect all sensor and harness wires at
HCU.
(4) Disconnect brakelines at HCU (Fig. 19). Mark
or tag lines for installation reference.
(5) Remove bolt and nuts attaching HCU mount-
ing bracket to fender apron and remove HCU.
HCU INSTALLATIONÐYJ
(1) Position HCU on fender apron (Figs. 2 and 19)
and install attaching bolts/nuts.
(2) Connect brakelines to HCU.
(3) Connect harness and sensor wires to HCU.
(4) Connect master cylinder reservoir hoses to
HCU.
Fig. 16 HCU Mounting (Left Hand Drive XJ)
Fig. 17 HCU Mounting (Right Hand Drive XJ)
Fig. 18 HCU Hydraulic Line Connections
5 - 54 ABS COMPONENT SERVICEJ

(5) Fill and bleed brake system.
COMBINATION VALVE REPLACEMENTÐXJ
The combination valve is not a repairable compo-
nent. The valve is serviced as an assembly whenever
diagnosis indicates replacement is necessary.
(1) Remove air cleaner housing for access to valve,
if necessary.
(2) Remove bolt attached valve to master cylinder
(Fig. 20).
(3) Disconnect pedal travel sensor harness connec-
tor and move harness wires aside for working access
if necessary.
(4) Disconnect pressure differential switch wires at
valve.
(5) Disconnect hydraulic lines at valve and remove
valve from vehicle.
(6) Connect hydraulic lines to valve.
(7) Position valve bracket on master cylinder and
install bracket attaching bolt.(8) Reconnect pressure differential switch and
pedal travel sensor wires.
(9) Bleed brake system. Refer to procedure in this
section.
COMBINATION VALVE REPLACEMENTÐYJ
The combination valve mounting bracket is perma-
nently attached to the valve. The bracket and valve
are serviced as an assembly.
(1) Disconnect harness wires from combination
valve switch.
(2) Disconnect brakelines attached to combination
valve.
(3) Remove nuts attaching combination valve
bracket to master cylinder mounting studs (Fig. 19).
(4) Remove valve and bracket as assembly.
(5) Start all brakelines in combination valve by
hand. Tighten line fittings just enough to prevent
leaks.
(6) Position valve mounting bracket on studs.
(7) Install and tighten nuts that attach combina-
tion valve bracket to studs on power brake booster.
(8) Connect wires to combination valve switch.
(9) Fill and bleed brake system.
(10) Final-tighten brakeline fittings to 18-23 Nzm
(160-210 in. lbs.) torque after bleeding brakes.
Fig. 19 HCU Mounting (YJ)
Fig. 20 Combination Valve Mounting (XJ)
JABS COMPONENT SERVICE 5 - 55

PARKING BRAKES
INDEX
page page
General Service Information................ 56
Parking Brake Adjustment (XJ/YJ)............ 63
Parking Brake Cable Tensioner Replacement (XJ).61
Parking Brake Front Cable Replacement (YJ) . . . 62
Parking Brake Lever Installation
(XJ with Full Console)................... 60
Parking Brake Lever Installation
(XJ with Mini Console)................... 58
Parking Brake Lever Installation
(XJ Without Console).................... 60
Parking Brake Lever Removal
(XJ with Full Console).................... 59
Parking Brake Lever Removal
(XJ with Mini Console)................... 58
Parking Brake Lever Removal (XJ Without Console).60
Parking Brake Operation................... 56
Parking Brake Pedal Installation (YJ).......... 61
Parking Brake Pedal Removal (YJ)........... 61
Parking Brake Rear Cable Replacement (XJ) . . . 62
Parking Brake Rear Cable Replacement (YJ) . . . 63
GENERAL SERVICE INFORMATION
Parking brake adjustment is controlled by a
cable tensioner mechanism. The tensioner mech-
anism is used on 1991 through 1994 YJ models
and XJ models starting with 1992 models. The
cable tensioner, once adjusted at the factory,
will not need further adjustment under normal
circumstances. There are only two instances
when adjustment is required. The first is when a
new tensioner, or cables have been installed.
And the second, is when the tensioner and ca-
bles are disconnected for access to other brake
components.
PARKING BRAKE OPERATION
The rear brakes are utilized for the parking brake
function. They are actuated hydraulically during nor-
mal brake operation but are mechanically actuated
for parking brake operation.
Parking Brake Components
The rear brakeshoes are applied by a system of le-
vers and cables for parking brake operation. A foot
or hand operated lever in the passenger compartment
is the main application device. Actuating levers on
the secondary brakeshoes move the shoes directly
into contact with the drum braking surface. The ac-
tuating levers are interconnected by a system of ca-
bles and a tensioner mechanism. The tensioner
mechanism controls parking brake adjustment.
On XJ models, the cable tensioner is part of the le-
ver assembly. On YJ models, the tensioner and
equalizer are mounted in a bracket attached to the
underbody.
On YJ models, the parking brake front cable is at-
tached to the foot pedal at one end and the cable ten-
sioner at the other. The tensioner is connected to the
equalizer which is the connecting device for the rear
cables (Fig. 1).
On XJ models, the cable tensioner is connected di-rectly to the hand lever (a front cable is not used).
The tensioner rod is attached to the equalizer which
is the connecting point for the rear cables (Fig. 2).
The rear cables are connected to the actuating le-
ver on each secondary brakeshoe. The levers are at-
tached to the brakeshoes by a pin either pressed into,
or welded to the lever. A clip is used to secure the
pin in the brakeshoe. The pin allows each lever to
pivot independently of the brakeshoe.
Struts, installed between each brakeshoe, are used
to maintain shoe alignment and equal motion when
the parking brakes are applied. Each strut is
equipped with a combination tension and anti-rattle
spring.
Parking Brake Application
To apply the parking brakes, the foot pedal is
pressed downward, or the hand lever is pulled up-
ward, to an engaged position. This pulls the rear
brakeshoe actuating levers forward, by means of the
interconnected tensioner and cables.
As the actuating lever is pulled forward, the park-
ing brake strut (which is connected to both shoes),
exerts a linear force against the primary brakeshoe.
This action presses the primary shoe into contact
with the drum.
Once the primary shoe contacts the brake drum,
force exerted through the strut does not end. Instead,
further lever movement continues to exert force
against the strut; only this time, in a reverse direc-
tion. The strut force then causes the secondary shoe
to pivot into contact with the drum as well.
The brakeshoes will remain engaged with the
drum until the levers and cables are released. A gear
type ratcheting mechanism is used to hold the pedal
or lever in an applied position. Parking brake release
is accomplished by means of the release handle on
YJ models. Or by the hand lever release button on
XJ models.
5 - 56 PARKING BRAKESJ

Fig. 1 Parking Brake Components (YJ)
Fig. 2 Parking Brake Components (XJ)
JPARKING BRAKES 5 - 57

PARKING BRAKE LEVER REMOVAL (XJ WITH MINI
CONSOLE)
(1) Release parking brakes, if necessary.
(2) Raise vehicle.
(3) Remove adjusting nut from tensioner rod (Fig.
2). Then secure equalizer and rear cables to chassis
with wire.
(4) Remove nuts attaching lever support plate to
underside of floorpan. Then move plate aside.
(5) Lower vehicle.
(6) Remove lever assembly from floorpan.
(7) Remove tensioner cover and boot for access to
lever arm (Fig. 3).
(8) Remove E-clip and pin that connect tensioner
to lever arm (Fig. 3).
(9) Remove lever attaching screws from floorpan
(Fig. 4).
(10) Remove lever assembly.
PARKING BRAKE LEVER INSTALLATION (XJ WITH
MINI CONSOLE)
(1) Assemble lever and tensioner components
(Figs. 3 and 4). Be sure E-clip is fully seated in pin
(Fig. 3).
(2) Verify that tensioner boot is properly seated in
cover (Fig. 5).
(3) Position lever assembly on floorpan and install
lever attaching screws, if equipped.(4) Raise vehicle.
(5) Insert cable tensioner rod in equalizer and in-
stall adjusting nut on tensioner rod.
(6) Install and tighten nuts that attach lever sup-
port plate to floorpan and lever screws.
(7) Adjust parking brakes. Refer to procedure in
this section.
(8) Lower vehicle and verify correct parking brake
operation.
Fig. 3 Tensioner E-Clip And Retaining Pin Location
Fig. 4 Mini Console And Parking Brake Lever Cover (XJ)
5 - 58 PARKING BRAKESJ

PARKING BRAKE LEVER REMOVAL (XJ WITH FULL
CONSOLE)
(1) Release parking brakes, if necessary.
(2) Raise vehicle.
(3) Remove adjusting nut from tensioner rod. Then
temporarily secure equalizer to nearby chassis com-
ponent with wire.
(4) Remove nuts attaching lever support plate to
underside of floorpan.
(5) Lower vehicle.
(6) On models with manual transmission, remove
shift knob, boot and bezel.
(7) On models with automatic transmission, re-
move shift handle cap and remove plunger, spring
and T-lock (Fig. 7).
(8) Remove shift handle and shift bezel (Fig. 7).
(9) Remove console cover screws (Fig. 8).(10) On models with power mirror switch, pry
switch out of console cover and disconnect switch
connector (Fig. 8).
(11) Remove console cover from base (Fig. 9).
(12) Remove console base.
(13) Disconnect brake warning light wire connec-
tor at lever.
(14) Remove lever and cable tensioner assembly
from floorpan.
(15) Move cover and boot aside for access to lever
arm (Fig. 3).
(16) Remove E-clip and pin that connect tensioner
to lever arm (Fig. 3).
Fig. 6 Hand Lever And Cable Tensioner Components (XJ)
Fig. 5 Tensioner Boot Seated In Cover
Fig. 7 Automatic Transmission Shift Handle
JPARKING BRAKES 5 - 59

PARKING BRAKE LEVER INSTALLATION (XJ WITH
FULL CONSOLE)
(1) Assemble lever and tensioner (Figs. 3 and 4).
Be sure E-clip is fully engaged in retaining pin (Fig.
3).
(2) Verify that tensioner boot is fully seated in
cover (Fig. 5).
(3) Position assembled lever and tensioner in floor-
pan.
(4) Connect brake warning light wires to switch on
lever.
(5) Install console base and cover.
(6) Connect power mirror switch wire to switch
and install switch in console cover.
(7) On automatic transmission models, install shift
bezel and shift handle.
(8) On manual transmission models, install boot,
bezel and shift knob.
(9) Raise vehicle.
(10) Insert tensioner rod in equalizer and install
adjusting nut on tensioner rod.
(11) Install nuts attaching lever support plate to
floorpan and lever.
(12) Adjust parking brakes. Refer to procedure in
this section.
PARKING BRAKE LEVER REMOVAL (XJ WITHOUT
CONSOLE)
(1) Raise vehicle.
(2) Remove nuts attaching lever support plate to
underside of floorpan.
(3) Remove adjusting nut from tensioner rod. Then
temporarily secure equalizer and cables to nearby
chassis component with wire.
(4) Lower vehicle.
(5) Raise lever cover at rear and tilt it forward
(Fig. 10).
(6) Remove cover attaching screws. Or, if cover is
attached with rivets, drill out and remove cover.
(7) Disconnect brake warning light wire at lever.
(8) Remove lever and tensioner assembly from
floorpan.
(9) Move cover and boot aside for access to ten-
sioner retaining pin and clip.
(10) Remove pin and E-clip that secure tensioner
to lever arm and separate lever and tensioner.
PARKING BRAKE LEVER INSTALLATION (XJ
WITHOUT CONSOLE)
(1) Assemble lever and tensioner (Figs. 3 and 4).
(2) Verify that tensioner boot is properly seated in
cover (Fig. 5).
(3) Position lever on floorpan and insert lever
screws through floorpan. Be sure lever cover and seal
are in place between lever and floorpan.
(4) Connect brake warning light wires to switch on
lever.
Fig. 8 Console Cover Screws And Power Mirror
Switch Connector
Fig. 9 Console Cover And Base
5 - 60 PARKING BRAKESJ