AR42.10-P-0015A Check Braking System For Leaks Using Pressure Tester

Checking Braking System For Leaks Using Pressure Gauge







Inspect

DANGER:
- Risk of poisoning from swallowing brake fluid. Risk of injury from brake fluid coming into contact with skin and eyes.
- Pour brake fluid only into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

CAUTION:
- See notes on externally invisible brake fluid loss
- See notes on repairs to brake system
- See notes on handling brake fluid

DANGER:
- Risk of death. Death may result if vehicle slips or topples from the lifting platform.
- Align vehicle between the columns of the lifting platform and position the four support plates at the lifting platform support points specified by the vehicle manufacturer.

1 Jacking up and supporting vehicle

CAUTION: See special instructions for lifting and supporting vehicle

2 Unscrew bleeder screw at brake caliper and connect to pressure tester (051)

CAUTION: Pressure testers for hydraulic fluid systems must not be used for systems with brake fluid, otherwise brake fluid may be mixed with mineral oil which may cause the brakes to fail.

NOTE: After testing, only bleed the brake caliper to which the pressure tester was connected.

3 Bleed pressure tester (051)
4 Switch off easy entry function for driver's seat and steering wheel
- Vehicles with memory and multifunction steering wheel.

CAUTION: Otherwise the driver's seat and steering wheel move to a different position, e.g. when the driver's door is opened/closed. The seat may be damaged if the brake pedal winch is installed.

NOTE: Switching off is effected by the buttons on the multifunction steering wheel in the convenience "menu" of the multifunction display, see vehicle operator's manual.

High-pressure
5 Run engine at moderate speed then create as great a vacuum as possible by suddenly releasing the accelerator pedal
6 Install brake pedal winch with adapter for brake pedal winch between brake pedal and seat

CAUTION: Protect brake pedal and seat against damage.

7 Depress brake pedal as far as possible with the brake pedal winch (080)

CAUTION: The pressure loss during the test duration of 5 minutes must not exceed 5 % of the regulated value.

Low-pressure check
8 Switch off engine and depress brake pedal until the vacuum is dumped.
9 Turn back brake pedal winch (080) until a line pressure of approx. 3 bar overpressure is still indicated on the pressure gauge

NOTE: The line pressure must not fall throughout the duration of the test (2 minutes).

10 Disconnect pressure tester (051)
11.1 Bleed brake system.
11.2 Bleed brake system with STAR DIAGNOSIS.