parking sensors FORD MUSTANG 1969 Volume One Chassis

02-02-07
Brake System

02-02-07

ANTI-SKID CONTROL SYSTEM

RELEASE PAWL CAM PIN

RELEASE PAWL CAM LEVER

RELEASE CABLE

H
1636-
A

FIG. 10—Parking Brake Control Assembly

With Manual Release—Typical

power unit with mounting bracket is

riveted to the control assembly. The

vacuum actuated piston within the

unit is connected by a rod to the

upper end of the release lever (Fig. 9).

The lower end of the release lever ex-

tends out for alternate manual release
in the event of vacuum power failure

or for optional manual release at any

time.

Hoses connect the power unit and

the engine manifold to a vacuum re-

lease valve in the transmission neutral

safety switch.
The anti-skid control system con-

sists of three major components (Fig.

39).
Mechanically driven electromag-

netic sensors at each rear wheel; an

electronic control module mounted

under the glove box; a vacuum pow-

ered actuator attached to a bracket on

the inside of the right front frame rail

under the toe board.

The sensors consist of steel rings

having teeth on their outer diameters,

pressed on each axle shaft just out-

board of the wheel bearing. The teeth

rotate past corresponding teeth on the

inside diameter of stationary steel

rings mounted in the bearing retain-

ers.
Also mounted in the retainers, are

ring-shaped permanent magnets and

coils of wire. Two wires from each

sensor connect the sensors to the con-

trol module.

The control module consists of solid

state electronic components sealed in

a container. It is connected to the sen-

sors and to a solenoid on the actuator.

The actuator is similar to a vacuum

brake booster and consists of three

parts.
A chamber divided by a vacuum

suspended diaphragm; a hydraulic cyl-

inder connected to the diaphragm; and

a solenoid connected electrically to the

control module.

IN-VEHICLE ADJUSTMENTS AND REPAIRS

After any brake service work, ob-

tain a firm brake pedal before moving

the vehicle. Riding the brake pedal

(common on left foot application)

should be avoided when driving the

vehicle.

BRAKE SHOE ADJUSTMENTS—

DRUM BRAKES

The hydraulic drum brakes are

self-adjusting and require a manual

adjustment only after the brake shoes

have been relined, replaced, or when

the length of the adjusting screw has

been changed while performing some

other service operation. The manual

adjustment is performed with the

drums removed, using the tool and the

procedure detailed below.

When adjusting the rear brake

shoes,
check the parking brake cables

for proper adjustment. Make sure that

the equalizer operates freely.
To adjust the brake shoes:

1.
Use Rotunda Tool HRE 8650,

(Fig. 11) to determine the inside diam-

eter of the drum braking surface.

2.
Reverse the tool as shown in Fig.

11 and adjust the brake shoe diameter

to fit the gauge. Hold the automatic

adjusting lever out of engagement

while rotating the adjusting screw, to

prevent burring the screw slots. Make

sure the adjusting screw rotates freely.

If necessary, lubricate the adjusting

screw threads with a thin, uniform

coating of MIC-100-A.

3.
Rotate Tool HRE 8650 around

the brake shoes to be sure of the set-

ting.

4.
Apply a small quantity of high

temperature grease to the points

where the shoes contact the backing

plate, being careful not to get the lu-

bricant on the linings.

5. Install the drums. Install Tinner-

man nuts and tighten securely.

6. Install the wheels on the drums
and tighten the nuts to specification.

7.
Complete the adjustment by

applying the brakes several times with

a minimum of 50 lbs pressure on the

pedal while backing the vehicle. After

each stop the vehicle must be moved

forward.

8. After the brake shoes have been

properly adjusted, check the operation

of the brakes by making several stops

while operating in a forward direction.

WHEEL CYLINDER REPAIR-

DRUM BRAKE

Wheel cylinders should not be di-

sassembled unless they are leaking or

unless new cups and boots are to be

installed. It is not necessary to remove

the brake cylinder from the backing

plate to disassemble, inspect, or hone

and overhaul the cylinder. Removal is

necessary only when the cylinder is

damaged or scored beyond repair.procarmanuals.com