S 430 (220.170) V8-4.3L (113.941) (2000)
Vacuum Brake Booster Check Valve: Testing and Inspection
Checking Check Valve
Shown On Model 220
1
Press the brake pedal several times until the vacuum in the brake booster is reduced
2
Connect tester (030) to brake booster
NOTE: Measuring connection (031) for checking the check valve (17) and/or brake booster (16).
3
Start the engine and produce a vacuum of 0.75 to 0.80 bar by opening the throttle and suddenly releasing the accelerator pedal
NOTE: Reduce vacuum > 0.8 bar by depressing the brake pedal.
4
Switch off engine
NOTE:
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Vacuum must not drop by more than 0.2 bar within 30 seconds.
-
Vacuum loss > 0.2 bar, replace vacuum line, if necessary, check brake servo
5
Disconnect tester (030) from brake booster