Brakes; Brake Diagnosis - Jeep 1979 CJ-5 Technical & Service Manual

26-1
BRAKES
SECTION INDEX
P a p
Brake Hydraulle System 26-20
Disc Brakes 26-39
Drum Brakes 26-32
Ganeral Information 26-1
Power Brake Units 26-29
Tools 26-54
G E N E R A L I N F O R M A T I O N
Page
General 21-1
Paring Brake Adjustment 26-1 i
Parking Brake Cables 21-18
Service Brake Adjustment 21-17
Specifications
26-19
Page
Brake Diagnosis
26-1
Brakelamp Switch
26-17
Brakelining Inspection
26-17
Brake Pedal 26-14
Brake Warning Lamp
26-14
l E N E I A l
Jeep vehicles are equipped with single piston, floating
caliper front disc brakes and self energizing rear drum
brakes.
Two different disc brake calipers are used. The caliper
used on CJ models slides on abutement surfaces ma-
chined into the caliper and caliper support bracket. The
caliper used on Cherokee, Wagoneer and Truck models
slides on pivot bolts installed in the support shield and
bracket assembly. Refer to the Brake Size and Appli-
cation Chart for size and application details.
Two different drum brake units are used. They are
similar in construction and operation but differ in
method of automatic adjustment. Eear drum brakes on
CJ models have cable operated automatic adjusters
while rear drum brakes on Cherokee, Wagoneer and
Truck models have linkage operated adjusters.
A dual reservoir master cylinder that provides sepa-
rate hydraulic systems for the front and rear brake
units is used on all models.
A three-function combination valve is used on all Jeep
models. The valve consists of a one-piece housing con-
taining a front brake metering valve, pressure differen-
tial warning valve, and rear brake proportioning valve.
Three power brake units are used. CJ models with
optional power assist brakes use an 8 inch (20.8 cm)
single diaphragm power unit. Cherokee, Wagoneer and
J-10 Truck models use a 9-1/2 inch (24.1 cm) single
diaphragm power' unit. J-20 Truck models use a 9-1/2
inch (24.1 cm) tandem diaphragm power unit.
Brake system preliminary diagnosis procedures are
outlined in Brake Diagnosis Guides A and B. Guide A
applies to all vehicles and Guide B applies to vehicles
equipped with power brakes only. Do not use Guide B
until all of the steps outlined in Guide A have been
completed.
The procedures outlined in the Brake Diagnosis
Guides are provided as a method for determining the
general problem area. After the general problem area m
has been defined, refer to the Power Unit, Disc Brake, m
and Drum Brake Service Diagnosis Charts to determine
the specific cause of a brake problem.
In most cases, an owner will describe a brake problem
as one or more of the conditions listed in the Service
Diagnosis Charts. However, to ensure an accurate diag-
nosis and avoid ineffective repair, road test the vehicle
(if possible), perform the procedures outlined in the Di-
agnosis Guides, and then consult the Service Diagnosis
Charts before attempting problem correction.