Brake Booster

[PaulES]

Hi,
I've been digging thru the past posts about the brake booster, but the information is a little sketchy and the links to rebuild directions seem to be invalid/old. So,

1) Since the rebuild sounds not-too-hard - does anyone have either the directions, or the link to them?

2) Isn't there also a company in Cal. that rebuilds them?

3) Just to make sure - I'm talking about the part, just the other-side of the firewall, that leaks onto my floormats under the brake pedal.

Any help is greatly appreciated!
regards,
Paul

[PaulES]

OK _ found this on the rebuild guys: (720) 566-0521 or www.bimmerhaus.com and talk to Dave Stackhouse or Jim Leithauser
Rebuild brake boost cylinder


I would still prefer to do it here, rather than ship mine out.

[chromeowner]

Brake booster kits and instructions

Contact me offline if you'd like a kit.

[RonP]

Excellent info....needed this 3 years ago!

[PaulES]

Thanks!
This is exactly the information I need.

Paul

[mlweaver]

Paul,
I've never heard of a brake booster leaking "onto my floormats".
The brake booster is not attached to the firewall, it is attached to the end of the brake master cylinder. The booster is filled with hydraulic fluid (pentosin) and usually leaks onto the garage floor between the firewall and the front left wheel.
The master cylinder is filled with brake fluid, and might leak into the cabin if the seal around the brake pedal push rod failed, but I've never seen this personally.
The master cylinder plus booster make one big assembly, but it is the master cylinder that is against the firewall and directly connected to the brake pedal. The brake booster features a "weep hole" on the bottom so that any leak of pentosin would drip directly down - I don't see how it could travel back to the cabin.
The most common fluid to leak into the front of the cabin is water/coolant from the heater core.

I'm not trying to be argumentative - just want to be sure you are on the right track. The brake booster is a huge job, and it would be a shame if you don't solve your problem after all that work.Mark W in mid-MO
2011 Cadi CTS coupe 6-speed
1993 BMW 850Ci 6-speed

[PaulES]

Hey Mark

This is the feedback I need. Unfortunately - I am in PA whilst the 8 is in CT - mechanic is also in CT so it seemed reasonable to get this resolved while I'm not driving the 8. Though it is difficult to talk about the problem without being able to look at the car.

Some years ago I (mechanical klutz that I am) ordered (from those guys in CO)the o-rings and spring to rebuild (what I thought was called) the brake booster. Getting to it involved removing everything down to the firewall, then disconnecting the brake pedal from the cabin. I have no faith in my car fixing skills and suspect that I reinstalled incorrectly.

1) Am I using the right or wrong name for this part?
2) I am pretty sure it is green Pentosin on the floor under the brake pedal.
3) I seem to remember removing the master cylander, ut only to get to the rest
4) Could the fluid be running down the rod that connect to the brake pedal?

Thanks - obviously I need it!

Paul

[mlweaver]

Hi Paul,
My bad - it sounds like you have leakage around the small internal seal around the push rod to the brake pedal.
In which case, be sure to get the kit from Bill that includes the internal (small) o-ring.
It sounds (from your description) that the repair several years ago involved the bigger o-ring that seals the front (outer) edge of the booster.
If it is pentosin, then leakage back along the rod is the only explanation.

It is (my opinion) easier to repair the booster by removing the booster and master cylinder from the car. It is POSSIBLE to do it without removal, but it was very tough for me.

I apologize for doubting your description - obviously I am fortunate to have only experienced the common front side leak from the booster, which presents as a pentosin puddle under the car.

Your names are correct - the booster is attached to the master cylinder. Bill (chromeowner) is very knowledgable and I'm sure his kit will have everything your mechanic needs to fix the issue once and for all.

Mark W in mid-MO
2011 Cadi CTS coupe 6-speed
1993 BMW 850Ci 6-speed

[mlweaver]

Apologies to everyone, and especially to Paul - I got my booster and master cylinder completely turned around.

Bill's link in the post below contains some great diagrams (and set me straight).Mark W in mid-MO
2011 Cadi CTS coupe 6-speed
1993 BMW 850Ci 6-speed

[PaulES]

Thank you Mark - I truly appreciate your concern and follow-up on this matter. Now I can proceed with more confidence.

Paul

[adciocca]

My gosh! I hope my problem does not involve this baby. I hope my master cylinder is the problem.
Thanks,
Antonio

1991 BMW 850i (black-USA)

[Mark in SBA]

Also, isn't that washing machine lid been seen around here before?

[chromeowner]

[Longhornlarry]

Hello,
Hope you can provide us with the power brake booster rebuild kit for a 1962 Ford Thunderbird. If not perhaps you can direct us to where we can find one. It seems everybody rebuilds your unit (3-4) week turnaround but no one sells the rebuild kits.

Larry Smith
Gulf Coast Classic Cars