Brake goes hard.

[funks]

Just wondering if anyone would help me with some advice. In 190D (2L), a brake pedal suddenly becomes hard and it is difficult to brake and the engine cannot be turned off from ignition key? Any idea what happened? I really appreciate some help guys. Thanks

 

[wireman]

YOU HAVE A POTENTIAL KILLER CAR.

The vacuum system is failing and the servo is not getting the power assitance it should.

You need to get the engine mounted vacuum pump checked along with the servo, its non return valve and the servo feed pipe (from pump to servo), there are several other vacuum consumers on your car these are the stop system, the head lamp leveling and heater controls. These extras are all connected to the main servo feed pipe and may have leaks, but since they are connected via restrictors should not be too much of concern for the apparent total loss of vacuum you seem to have suffered. Look at the pipe nut onto the servo's housing, it may be loose. There is a possibility that the vacuum pump requires replacement at about £150.

good luck.

 

[funks]

I have checked the servo's pipe nut and it is tight. I have looked at the vacuum pump at idle and smoke coming somewhere near it. It looks there is a leak somewhere.., Do you think I can change the pump myself or get somebody to do it.
Thanks a lot wireman, your help is really appreciated.

 

[wireman]

It is not difficult to change the pump, however do make sure that the servo body (forgot to list that yesterday) and non return valve are in good order before you swap it and spend money on parts that are not needed.

Find a trustworthy independent and ask them if you are uncertain and need help, it will be much cheaper than using MB.