Just wanted to see if anyone else has had this ...

Brake pedal is very hard to press on cold start in morning .. it is fien there after while driving ..

Now I only started noticing this last two days and am now not sure if it always been the case or if something is at fault ..

Had a quick look round and it seems the brakes are loosing vacuum over night .. and can be caused by a faulty brake booster or vacuum pipe to the brake booster ??

Car is E60 2005 530d

Any ideas or anyone had or seen this problem before ??

Cheers

You may have a leaky vacuum pump as well. I am not certain of the exact location on your engine, but it should be in the front on the engine block towards the radiator. If the brake pedal feels hard, you might have some oil in the vaccum lines and/or brake booster. It could turn out to be very expensive if you let it go too long.

Cheers for that mate ...

Im going to have a proper look this weekend .. has been mention that a pipe may have come off or split going to the pump ...

Could also be the one way check valve is not working. Either way you will soon find out https://5series.net/forums/public/st...t/thumbsup.gif

the check valve is on the vacuum pipe, correct? i'm getting similar symptoms

Not sure on the BMW but most cars have it at the junction where the vacuum line meets the booster. Basically it is a one way valve to keep vacuum in the booster when the car is off or not producing vacuum.

edit- I looked it up and it is part of the hose assy


Attachment 111320

i'm pretty sure that's my problem, if I have my foot on the brake when I turn the car off the pedal gets hard and pushes back up. i know that's not supposed to happen.

cheers for the help so far ..im going to have a look this weekend and will report back .. have spoke with my local stealers and they havent sold any brake booster ( or servo as it called ) at all .. they dont think it a common problem ....
Ill try the hold brake down and switch car off .. see what happens ...

Im glad im not only one with this problem as I thought i was going mad lol ....

Hi,

I had the same problem (05 545i). The vacuum hose was cracked (rubber that connects to the vacuum pump). See the pix.

Let us know what did you find.

replaced the line, including the check valve, to no avail. Getting new brake booster thanks to CPO.