Brake Problem with my Z4

[richard in NC]

After almost a year and 10,000 miles of flawless fun driving with the Z4 except for moisture in a tail light, my Z4 is in the shop with a major problem. The other night after going somewhere after work, I hit the brake pedal as usual to start it up. I may have pressed on it hard while reaching for something but none the less, I heard a loud crack under the dash. Once I started the car, I noticed an odd feel to the pedal. I got a hissing sound followed by a really hard pedal and had to really stomp on it just to slow the car. Its as if I broke the power brake booster. I carefully drove the car home. Fortunately there was no traffic and I had plenty of room to slow from speed at all times. Well this morning I called BMW Assist and had the car put on a flat bed and taken to a dealer. They just called. It's not a simple fix and they'll have to dig into it Monday when the main techs work.

[Vintage]

that you for the bad news and please keep us updated. i have never heard of this problem before. hopefully you will not be without the Z for too long

[T89]

This is worrying. Keep us updated.


T

[teagueAMX]

Originally Posted by richard in NC

After almost a year and 10,000 miles of flawless fun driving with the Z4 except for moisture in a tail light, my Z4 is in the shop with a major problem. The other night after going somewhere after work, I hit the brake pedal as usual to start it up. I may have pressed on it hard while reaching for something but none the less, I heard a loud crack under the dash. Once I started the car, I noticed an odd feel to the pedal. I got a hissing sound followed by a really hard pedal and had to really stomp on it just to slow the car. Its as if I broke the power brake booster. I carefully drove the car home. Fortunately there was no traffic and I had plenty of room to slow from speed at all times. Well this morning I called BMW Assist and had the car put on a flat bed and taken to a dealer. They just called. It's not a simple fix and they'll have to dig into it Monday when the main techs work.

Did they tell you what the actual fix is? I would agree with you that is sounds like a power brake booster. Typically they are relatively easy to remove and replace, but yours looks really buried so I don't know if that fits their description of a simple fix.

It is very disconcerting that a failure of that type happened. Glad you weren't flying down the freeway!

.

[Mr. ///M3 RD]

Richard, sorry to hear it, do keep us posted. I have the same model and engine.

[teagueAMX]

One thing about brakes is they are considered "fail safe", meaning when the fail, and all things mechanical will fail, they fail in a safe way. So even though richard in NC may have lost his power assist booster, the brakes themselves continued to operate.

[KrisNL]

Wow Richard, that is bad news. Keep us updated.

[Otago]

Vacuum pump failure?

[teagueAMX]

Originally Posted by Otago

Vacuum pump failure?

No. If it was a diesel, maybe. But the way he describes the failure was something you could clearly hear from inside the cab.

[richard in NC]

Definitely the brake booster. It was over-nighted and replaced under warranty. So yes, some parts do exist in the BMWNA inventory. They can't say why or what broke but sent it to BMW for analysis. Doubt I'll ever hear back. They also did a low mileage oil change (10,000 in 12 months), replaced the wipers, did a state inspection, and did an alignment (my request due to excessive tire wear).

I drove a 328i with sport package for 2 days. Not bad but I missed the Z4. Especially with the top down weather we had.

At least I can take the Z4 down to Spartanburg, SC for 2 days of fun at the BMW PC. One day is a corporate event with training in the morning and track time in the afternoon. Friday will be my BMW 101 "Mock Delivery" Experience. I signed up for this a year ago and finally get to do it. I hope they have a Z4 35i DCT for the on-track portion. That's why I waited in the first place.... I do a new thread with pics for it.