E46 Brake Pedal feels hard and wont depress. Advise needed

[Lloyd09]

Vehicle: 2004 E46 318ti

The brake pedal on my vehicle wont depress and requires alot of effect to stop the car.
From a few quick tests I gather there is a vacuum issue which points to the brake booster.

I've spoken to a reliable mechanic and he says it could be the check valve on the booster itself, he says he has only replaces 3 bmw boosters in his decades of experience with the brand. apparently these booster last a long time. I will be dropping the car off next week.

I'm curious if any of you as had the same problem and if so, what was the fix.

 

[Bazza]

Have you tried starting the car?:fencelook:

 

[Lloyd09]

Have you tried starting the car?:fencelook:

Seriously Mate? lol

 

[Jeremy.d]

Have you tried starting the car?:fencelook:

:roflol:

 

[Straight six]

:roflol::roflol::roflol::roflol::roflol::roflol::biglol:

 

[VictorMike]

Your problem is rare, but I would hazard a guess and say one or more components of your brake booster has failed.

 

[Nobz330i]

Have you tried starting the car?:fencelook:

Lmfao:biglol:

 

[Lloyd09]

Your problem is rare, but I would hazard a guess and say one or more components of your brake booster has failed.

Yip.... I have a feeling it could be a leak in the hose running from the booster(losing vacuum). Could have a leak on one of the joints. Will have a proper look at it.

 

[Bazza]

Sorry, didn't mean to derail the thread.

Hope you find the solution and get the issue sorted ASAP. IMO it does sound like symptoms of a bad brake booster.

 

[SMN325]

Have you tried starting the car?:fencelook:

:crazylaugh:

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Hope this helps:

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-vacuum-brake-booster-check-valve

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Hope this helps:

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-vacuum-brake-booster-check-valve

 

[Dewald Basson]

When last did was the system fluid changed?

If there was a leaking hose the pedal would get softer, no? Because there is no "pressure" to press against? Or just could just be the booster that is kaput.

 

[VictorMike]

When last did was the system fluid changed?

If there was a leaking hose the pedal would get softer, no? Because there is no "pressure" to press against? Or just could just be the booster that is kaput.

If the vacuum hose to the pump is broken, it would also get hard, just as if the car was off.

 

[zippy320]

before you replace the Brake Booster , Check the vacuum pump , its attached at the back of the engine onto ( I think the camshaft? ) by 3 bolts . Take it off the car , open it up and look at the condition of the seal as well as that thing that spins in there , Also blow into the in/outlet , I think blowing in should have resistance or something like that , I cant remember but its a one way valve that the pipe plugs into . The valve on the Vacuum pump can fail and cause this issue sometimes it gets stuck , sometimes it allows air through both ways . If the pump seems fine , then while you are in there , buy the seal replacement kit for the vacume pump and replace the seal so its sort of as good as new .

While you are checking the pump , check the pipe and the valve that goes from the brake booster to the vacuum pump . The pipe should sit flush into the brake booster , and the valve should work the same as the valve on the vacume pump .

Chose those things before replacing the booster , Those boosters don't fail very often . I know because its one part that seems to be plenty full at scrap yards I visit , and commonly misdiagnosed .

 

[francoishensen11]

before you replace the Brake Booster , Check the vacuum pump , its attached at the back of the engine onto ( I think the camshaft? ) by 3 bolts . Take it off the car , open it up and look at the condition of the seal as well as that thing that spins in there , Also blow into the in/outlet , I think blowing in should have resistance or something like that , I cant remember but its a one way valve that the pipe plugs into . The valve on the Vacuum pump can fail and cause this issue sometimes it gets stuck , sometimes it allows air through both ways . If the pump seems fine , then while you are in there , buy the seal replacement kit for the vacume pump and replace the seal so its sort of as good as new .

While you are checking the pump , check the pipe and the valve that goes from the brake booster to the vacuum pump . The pipe should sit flush into the brake booster , and the valve should work the same as the valve on the vacume pump .

Chose those things before replacing the booster , Those boosters don't fail very often . I know because its one part that seems to be plenty full at scrap yards I visit , and commonly misdiagnosed .

Agreed, replaced two of these pumps on the N42, both cars brake pedal was hard AF while idling, almost like pumping the brakes with the ignition off, replaced the vacuum pumps on both and it was all good, both occasions the guys came and was misdiagnosed, people told them brake booster, which it wasn't.

Sent from Cape Town

 

[Lloyd09]

Good morning Gents

Thanks for the replies. I've found the problem, it was a sticky booster check value. It wasnt holding vacuum in the system. Part cost R40 from Goldwagen :=):
But will be checking for an OEM part.

Thanks again for the help!

 

[Rayzor]

Good morning Gents

Thanks for the replies. I've found the problem, it was a sticky booster check value. It wasnt holding vacuum in the system. Part cost R40 from Goldwagen :=):
But will be checking for an OEM part.

Thanks again for the help!

Glad you found the culprit and thanks for sharing :coolShake:

 

[SMN325]

Good morning Gents

Thanks for the replies. I've found the problem, it was a sticky booster check value. It wasnt holding vacuum in the system. Part cost R40 from Goldwagen :=):
But will be checking for an OEM part.

Thanks again for the help!

that's good news.

 

[Lloyd09]

Update: Problem solved!!!!!!

The booster was cooked but my concern is how it got damaged.


My story :

I've replaced the check valve and decided to fit a new vac pump ( instead of refurbishing the old) but the problem still persisted.

I sent the car to a trusted mechanic to have the booster checked out. He confirmed that the brake booster was causing the hard pedal
Had the brake fluid flushed and the booster refurbished. Brakes feel great.

My concern however is that my mechanic reported that traces of petrol was found in the booster causing it to fail. He is 100% sure it is petrol and not oil!
So our question is..... How on earth did petrol get in there?

A while back i sent the car to BMW northcliff for the airbag recall and noticed that the brakes felt "weird" (spongy and at times slightly harder to press) the same day I fetched the car. I didnt think much of it and continued driving it as the symptoms were very slight. A month later the booster diaphragm is damaged, causing the hard brake pedal.

Gents, I cant prove that the guys at the dealership sabotaged the booster but I urge you guys to be cautious. If you notice something odd after they have worked on your vehicle ( no matter how small it is) please report it to them immediately.