Bypass Condition Test; Non-Pressure Leaks - Ford Transit 2002 Owner's Manual

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 tire
pressures, grease or fluid on the brake shoes and linings, damaged brake shoes and
linings, incorrectly adjusted parking brake, or damaged or contaminated brake pressure
control valves.
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. 1. Check the fluid in the brake master cylinder reservoir. Fill the brake master
cylinder reservoir if low or empty.
2. 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 the NEUTRAL position. Raise and support the vehicle.
REFER to: Jacking (100-02 Jacking and Lifting, Description and Operation) /
Lifting (100-02 Jacking and Lifting, Description and Operation).
Apply the brakes with a minimum of 445 N (100 lb) and hold for approximately 15 seconds.
With the brakes still applied, exert a torque on the front wheels of 10.1 Nm (75 lb ft). If
either wheel rotates, install a new brake master cylinder.
REFER to: Brake Master Cylinder - LHD FWD
and Installation) /
Brake Master Cylinder - RHD FWD
Installation).

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 brake 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 brake master cylinder reservoir mounting seals.
Service such a leak by installing new seals.
(206-06 Hydraulic Brake Actuation, Removal
(206-06 Hydraulic Brake Actuation, Removal and
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