Bad Booster?

[glucklich21]

So I just finished up my 24v swap. I went to go for a little test spin and noticed my brakes didn't do squat. The pedal is super firm and will not budge except for maybe an inch, if that. It's like stopping with no brakes at all. What little distance I can pump, makes no difference.

So far diagnosing I made sure the direction of the check valve was correct and even removed it. Next up would be to check the condition of the oring on the master, but I don't recall it looking bad during install.

The setup in question is a E32 (aka IX) booster with an E36 M3 25mm master cylinder.

How likely is it that my booster is bad? If so, what interchanges that will fit that same master cylinder?

[NeverEnough02]

I have the same issue. I was told by a guy who has done over 200 of these swaps that he has never seen a bad booster but the IX booster and a new IX master would be needed for the swap. He does everything as a bolt on so the IX would fit without mod if you create a remote reservoir. I am not sure if the IX specific is due to fit or due to the 24v makes less vac making the IX a better match for less vac pressure.

[Gooch]

I would imagine it would be possible to rip the diaphragm if you were a little vigorous modding the pushrod.

But pop the master off the booster and just pull it back to check if the O-ring is there. When I did the booster upgrade on my 535i I had the exact same symptoms because the O-ring fell off in my drain pan and I never noticed.

[glucklich21]

I would imagine it would be possible to rip the diaphragm if you were a little vigorous modding the pushrod.

But pop the master off the booster and just pull it back to check if the O-ring is there. When I did the booster upgrade on my 535i I had the exact same symptoms because the O-ring fell off in my drain pan and I never noticed.

I didn't modify the pushrod. The spacer and such are still there.

I pulled the MC off tonight to look at the o-ring. While it doesn't look in bad shape it did seem kinda loose for the application. I remember the o-ring on my other E36 M3 MC on my S50 car being very tight around the MC. So I'm going to stop by the dealer tomorrow and order one.

With the MC off, I pushed in the brake pedal and heard the typical "woosh" noise as it came back from the floor, so I'm pretty sure it's good at this point. Hopefully the o-ring solves it.

[glucklich21]

I have the same issue. I was told by a guy who has done over 200 of these swaps that he has never seen a bad booster but the IX booster and a new IX master would be needed for the swap. He does everything as a bolt on so the IX would fit without mod if you create a remote reservoir. I am not sure if the IX specific is due to fit or due to the 24v makes less vac making the IX a better match for less vac pressure.

The IX/E32 booster (same minus the Giring label position and the clevis length) gives the clearance for the intake manifold to clear after some light grinding away of the outer fins of the intake. It more or less bolts right in and you gain a double diaphram booster. The remote reservoir isn't required if you remove the rear spacer mount and rethread the pushrod.

[NeverEnough02]

The IX/E32 booster (same minus the Giring label position and the clevis length) gives the clearance for the intake manifold to clear after some light grinding away of the outer fins of the intake. It more or less bolts right in and you gain a double diaphram booster. The remote reservoir isn't required if you remove the rear spacer mount and rethread the pushrod.

So not as wide as the OEM version and ads a double diaphragm. Got it. What does a double diaphram provide?

I have read that you can not use the bracket and have enough space for the resi. Then you have to modify the pushrod. The guy I had look at my car doesn't roll on that philosophy. He swaps and gives a full parts list so you can bring your car to the dealer with his parts book and the dealer can replace anything on the spot with off the shelf parts. Expensive but convenient.
Would a smoke test indicate a leak at the oring?

[Gooch]

Any progress?

[glucklich21]

Ordered a new o-ring and that came in. Installed it and my battery was drained. I've been out of town since then. So hopefully some good news to report tomorrow when I jump start it.

[NeverEnough02]

Ordered a new o-ring and that came in. Installed it and my battery was drained. I've been out of town since then. So hopefully some good news to report tomorrow when I jump start it.

How did it go?