34 00 009 Checking Brakes on Test Stand

34 00 009 Checking brakes on test stand






Important!
Only brake test stands with test speeds of 2.5-6 km/h may be used.
Before driving onto the brake test stand (dynamic brake analyser), switch off the Hill Descent Control (HDC) and keep it switched off while testing the brakes.
The HDC indicator lamp must not light up!

Note:
It is possible for the HDC indicator lamp to go out or not to light up even when HDC mode is activated if HDC is temporarily unavailable on account of high operating temperature.






Necessary preliminary tasks:
- Check tyres for damage
- Check tyre treads
- Checking tyre inflation pressure
- The brakes must be at normal operating temperature. For this purpose, gently warm up the brake discs while dry by braking the vehicle several times.






Important!
For testing, turn on the ignition and make sure the transmission selector lever is in the "N" position.
Comfort access: insert remote control in ignition lock.

Note:
If the remote control is not inserted in the ignition lock, the "P" transmission position is selected automatically after approx. 30 minutes.

Failure to comply with this instruction may result in damage to the test stand or to the vehicle.






Visual and function checks of actuating and warning devices.

Front brakes:
- Drive vehicle with front axle into roller dynamometer
- Move transmission selector lever to "N" position
- Start roller dynamometer
- Press service brake pedal
- Read off maximum brake power on left / right



Rear brakes:
- Drive vehicle with rear axle into roller dynamometer
- Move transmission selector lever to "N" position
- Start roller dynamometer
- Press service brake pedal
- Read off maximum brake power on left / right



Parking brake:

Important!
The test may only be carried out with the engine switched off, the transmission selector lever in the "N" position and the ignition switched on.

Note:
The electromechanical parking brake can not be tested on a plate test stand!

- Drive vehicle with rear axle into roller dynamometer
- Move transmission selector lever to "N" position
- Turn off engine.
Note: When the engine is running, additional braking action will otherwise be exerted by the DSC system on all the wheels.
- Turn on ignition
- Start roller dynamometer






- Activate parking brake, pull button (1) for this purpose
Note: Parking brake indicator lamp in instrument cluster lights up red. Duo-servo brake (actuating unit) is applied. Roller dynamometer shuts down after locking of wheels (slip) or vehicle is pushed out of roller dynamometer
- Deactivate parking brake:
- Press button (1) and simultaneously press service brake pedal
Note: Duo-servo brake (actuating unit) is released.

- Read off maximum brake power on left / right