Abnormal Conditions; Bypass Condition Test; Non-Pressure Leaks - Ford 2002 Bantam Workshop Manual

206-00-18
DIAGNOSIS AND TESTING (CONTINUED)
fluid level (i.e., after brake application and
release) will remain unchanged.
• A trace of brake fluid will exists on the brake
booster shell below the master cylinder-
mounting flange. This results from the normal
lubricating action of the master cylinder bore
end seal.
• The fluid level will fall with brake shoe and
lining wear.

Abnormal Conditions

NOTE: Prior to performing any diagnosis, make
sure the brake system-warning indicator is
functional.
Changes in brake pedal feel or travel are
indicators that something could be wrong with the
braking system. The diagnostic procedure and
techniques use brake pedal feel, warning
indicator illumination and low brake fluid level as
indicators in diagnosing braking system
concerns. The following conditions are
considered abnormal and indicate that the brake
master cylinder is in need of service.
• The brake pedal goes down fast. This could
be caused by an external or internal leak.
• The brake pedal eases down slowly. This
could be caused by an external or internal
leak.
• The brake pedal is low and or feels spongy.
This condition may be caused by no fluid in
the brake master cylinder reservoir, reservoir
cap vent holes clogged or air in the hydraulic
system.
• The brake pedal effort is excessive. This may
be caused by a bind or obstruction in the
pedal or linkage, clogged fluid control valve or
insufficient booster vacuum.
• The rear brakes lock up during light pedal
force. This may be caused by incorrect tyre
pressures, grease or fluid on the brake shoes
and linings, damaged brake shoes and
linings, incorrectly adjusted parking brake, or
E1092 EN
Brake System — General Information
damaged or incorrectly adjusted Load Active
Valve.
• The brake pedal effort is erratic. This
condition could be caused by a brake booster
malfunction; extreme caliper piston knock
back or incorrectly installed brake shoes and
linings.
• The brake-warning indicator is ON. This may
be caused by low fluid level, ignition wire
routing too close to the fluid level indicator
assembly, or float assembly damage.

Bypass Condition Test

1. Check the fluid in brake master cylinder. Fill
the brake master cylinder reservoir if low or
empty.
2. Observe the fluid level in the brake master
cylinder reservoir. If after several brake
applications, the fluid level remains the
same, measure the wheel turning torque
required to rotate the wheels with the brakes
applied as follows:
Place the transaxle in NEUTRAL and raise and
support the vehicle. REFER to Section 100-02.
Apply the brakes with a minimum of 445 N and
hold for approximately 15 seconds. With the
brakes still applied, exert a torque on the front
wheels of 10.1 Nm. If either wheel rotates, install
a new brake master cylinder.

Non-Pressure Leaks

Any empty brake master cylinder reservoir
condition may be caused by two types of non-
pressure external leaks.
Type 1: An external leak may occur at the master
cylinder reservoir cap because of incorrect
positioning of the gasket and cap. Reposition the
cap and gasket.
Type 2: An external leak may occur at the
reservoir mounting seals. Service such a leak by
installing new seals.
206-00-18
07/2001 2002 Bantam