[tmick5jr]

Hey everyone, just bought a 2006 325i that has a problem with the brakes. Allow me to explain. When pressing the brake pedal while the car is OFF the pedal pushes down fine without issue and goes back out without issue as well. But when I start the car the brake pedal immediately sends itself to the floor all the way down and I have to manually pull the brake pedal off the floor just for it to bring itself back to the floor again. Anyone have this happen to them before and what solved the issue? I noticed on one of my vacuum lines coming from the vacuum booster was cracked at the very end. Could that be the cause? Thank you!!

[335i54n]

yes. youre missing the firewall piece it seems, that also act as a support for that line

[tmick5jr]

Originally Posted by 335i54n

yes

So if there was a leak in that line it would cause the pedal to go straight to the floor when the car starts? And also do you know how to remove that piece that's still connected? Does it just pull straight out?

[335i54n]

you need a new hose, see that white clip thats where it supposed to disconnect but the line cracked and broke off the barb

[tmick5jr]

Originally Posted by 335i54n

you need a new hose, see that white clip thats where it supposed to disconnect but the line cracked and broke off the barb

Okay so just squeeze that white clip and it should just pop out?

[tmick5jr]

Replaced that hose, brake pedal is still pulling itself straight down to the floor when the car starts. I don't understand. When I turn the car off the pedal rises back up to its normal position, but when I start it, it brings itself back to the floor and I have zero braking ability. There are no leaks in the system.

[Brian86]

So you're saying the car actively sucks the pedal to the floor, all by itself? Are the brakes applied when it does that? or no?

That's wild. Never seen that before.

It has to be the brake booster assembly and/or master cylinder. I have no idea what specific malfunction would cause it though. Some combination of internal vacuum and hydraulic leaks.

Grab the entire mess out of a salvage yard to pop on there.

[tmick5jr]

Originally Posted by Brian86

So you're saying the car actively sucks the pedal to the floor, all by itself? Are the brakes applied when it does that? or no?

That's wild. Never seen that before.

It has to be the brake booster assembly and/or master cylinder. I have no idea what specific malfunction would cause it though. Some combination of internal vacuum and hydraulic leaks.

Grab the entire mess out of a salvage yard to pop on there.

Yes it actively sucks the pedal to the floor by itself when the car starts without me touching it. If I try to pull it out it's very difficult and just sucks itself back down. But when I shut the car off, the pedal releases itself to its normal position. When I pump the brakes when the car is off it feels normal, they press down and release like a regular car would. It's only when it's running. I guess it could be the booster itself? It's just weird because although it's a 2006, it only has 52k miles on it.