Brakes slowly tightening up

[Crippled Crip]

Hey guys, so, my 325e's brakes have been acting strange. A few weeks ago, was out for a midnight drive through the hills and as I was going back up the hill, my car started to lose power slowly and slowly, and eventually once I got over 45, the car would start shaking completely. I pulled over to the side of the road, and my brakes were red hot and really smoky. I let the brakes cool off completely, and after an hour, took it back home without any issues.

So, we checked out the brakes, and the brake lines were dirtry, so we completely flushed them. So, I assumed it was that, as the car was driving just fine after that, and I drove it for about 3 weeks without any hiccups. Now on Thursday, I drove from Santa Barbara to orange county. As I was going through LA, I was again, going up a hill on the 405, and started losing power again until eventually the car started shaking completely and I had to pull off. So, I pulled off to the side of the road, and let it cool for about 20 minutes. After 20 minutes, I was on the road and the car was driving fine. After about 70 miles, it starts happening again, and I pull over and let it sit for 30 minutes. After 30 minutes, I get back in, and the car won't move, as if the ebrake I still on. And an hour after that, the brakes loosened up, but the car was not driveable.

The car is back home now, but we are stumped. Any suggestions on what it could be?

Thanks

[jlevie]

If only some the wheels have this problem I'd suspect sticking calipers. But if it is happening to all of the wheels I'd suspect the brake booster. It could be that there isn't enough free play in the pedal (adjustable via the clevis rod), or that the relief valve in the booster is bad.

[Crippled Crip]

If only some the wheels have this problem I'd suspect sticking calipers. But if it is happening to all of the wheels I'd suspect the brake booster. It could be that there isn't enough free play in the pedal (adjustable via the clevis rod), or that the relief valve in the booster is bad.

Yeah forgot to add that, its only the fronts.

[netcsk]

My car did this many years ago after I had a failed front soft brake line. Popped a line, fixed it, bled it, and had issues with the brakes slowly tightening up.
My issues would only occur when I would use the brakes. After a certain number of times using them, they would tighten up. I could 'fix' it by pushing the brake petal very hard and they would release for a short time.
The problem wound up being a bad brake booster. When my foot went to the floor, it must have damaged it.

Not saying that is your problem, but that was my experience.

[Crippled Crip]

My car did this many years ago after I had a failed front soft brake line. Popped a line, fixed it, bled it, and had issues with the brakes slowly tightening up.
My issues would only occur when I would use the brakes. After a certain number of times using them, they would tighten up. I could 'fix' it by pushing the brake petal very hard and they would release for a short time.
The problem wound up being a bad brake booster. When my foot went to the floor, it must have damaged it.

Not saying that is your problem, but that was my experience.

Thanks, I'll definitely look into that.

Was it only the fronts? Or was it all around?

[netcsk]

Thanks, I'll definitely look into that.

Was it only the fronts? Or was it all around?

I'm actually not quite sure. It would have made sense for it to have been all four corners, though.

[Davidov]

Same problem. Check this out.

http://www.r3vlimited.com/board/showthread.php?p=3879105#post3879105