Febi outlines a common fault affecting Mazda 3 I and II and Mazda 5 I and II’s brake hose. The relevant febi part numbers are ADM55390 and ADBP530000.
The brake warning light in the instrument cluster stays illuminated when the handbrake is released, and the brake pedal feels soft. The fluid level in the master cylinder is below the minimum line, and an external examination under the vehicle reveals a pool of fluid on the ground by either of the rear wheels.
Cause
The rear flexible brake hose is prone to corrosion where it joins the brake pipe. This hose has a rubber protective sleeve that provides it extra support, but this sleeve also traps moisture and debris from the road, causing the metal components within to corrode. This then compromises the connection, leading to a potential failure occurring when the brakes are applied, especially in an emergency situation.
Solution
The brake systems on the above models should be inspected regularly, and if any of the hoses are showing signs of corrosion affecting the metal unions they should be replaced as a matter of urgency.
