Hi,
C200k WDC203 has a hard brake pedal feel, mainly after a cold start and very intermittent. Faulty vacuum pump or open pump circuit is logged and will not reset. Should the pump work continuously with engine idling? Am I on the right track replacing the pump??

Check this out.

Attached Files

Electric Booster.pdf (16.3 KB, 374 views)

Thank you very much for the reply, I have since taken the top cover of my vacuum pump and it's seized alright which explains no vacuum at idle. Now should this pump run continuously??