34 00 519 Checking Service Brake: High- And Low-Pressure Tests

WARNING: This page is about a different car, the 2010 BMW X5, 2009 BMW X5, 2008 BMW X5, and 2007 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The high/low-pressure test (leakage test) must be carried out with the engine switched off.

Observe safety instructions on raising the vehicle. See LIFTING VEHICLE WITH A LIFTING PLATFORM

High-pressure test (leakage test):

Perform test on both brake circuits.

1st brake circuit, front axle

2nd brake circuit, rear axle

Remove bleeder screw, connect pressure tester and bleed.

Load brake pedal with a force and block brake pedal with pedal support, refer to TESTING AND BLEEDING BRAKES E70

After 2 minutes, pressure is permitted to drop by max. 8 %.

Low-pressure test:

Perform test on both brake circuits.

Reset pedal support until test pressure in braking system is 2 ... 5 bar.

Vehicle and measuring apparatus must remain steady as vibrations will distort the result.

Pressure must remain constant for a test period of 5 minutes.

Check all rubber parts in case of excessive pressure drop.

Bleed brake calipers and wheel brake cylinders after finishing test.