My BJ8 is constantly loosing brake fluid. There are no leaks anywhere. Brake cylinders have been changed, fluid has been bled according to manual. Theory is that the power booster is allowing fluid to be sucked into the engine via the vacuum hose. Is this correct? Is there a reliable alternative to replacing it?

Thanks for any help.

Cliff

Cliff -

If you have white smoke coming out the back, then it's leaking through the power booster to the motor. If not, it's just filling up one side of the power booster's cylinder. That means that after a while, you won't have power brakes because the whole thing will be full of new & expensive brake fluid.

The only real fix is to either rebuild your old Girling Power Booster (only a 50/50 chance of it working long term or not if you do it yourself) or if you drive your car every day get a PBR booster(from Australia)or a Lockheed copy Powertune servo from the UK (which typically can be had for about 90 pound from the UK, or $200 ++ in the US).

If you insist on keeping your original Girling booster, it is recommended that the booster is resleeved with a SS insert and the unit rebuilt by someone knowledgeable about these units.

After my engine rebuild, it seems like my fluid loss got worse. I took the booster out a month or so ago. I took at least a 1.5 cups of fluid out of the booster, but the performance was still good. I sent in another spare booster to Powerbrake Exchange in San Jose to have it rebuilt. It wasn't right so I sent it back Friday. Low boost and brakes were locked on after a long period parked, but they released right away. Powerbrake has done good work for me in the past, so I expect satisfaction eventually. I understand the PBR has a lot more boost than the Girling. I think the feel of the Girling is just right.

Yes Power Brake Exchange does good work.But sometimes even the pros do not get it right. However, I can not think of anyone else I would choose to rebuild my booster.--KEOKE

When I rebuilt mine 32 years ago it would "stick". After much experimenting I finally fixed the problem by taking the rubber grease that came with the kit, plus purchasing another tube of it, and worked it into the cylinder that seals the leather type of "o ring" to the piston. I worked the grease into the metal much like you would do when waxing a car.
It is still in the car and has not had any repairs since then.
Patrick

Hi Patrick, that canister is suppose to have a dry lubricant like Molly sprayed in it that is similar to a paint. This is to say it adheres permanently to the canister's metal. Several years ago I located a shop in Texas that could supply this material as well as comp;ete proper fitting rebuild kits. Over the years I have lost the information. However, that lube you used is a substitute for what is required. I think the rebuilders have a source but do not sell it.--FWIW--KEOKE

Was this the dry lube spray?

http://www.sandstromproducts.com/pdfs/e736.pdf

Hi Randy, Yes I belive that is the product they were selling along with their kits. ---Keoke

For what it's worth, I have just gotten myself set up again to apply polymer coatings. I'm currently building a BMW M Rdstr engine using a full complement of dry-film lubricant, thermal barrier and thermal dispersant coatings.

Applying the dry-film to the inside of the "big drum" and putting the thermal dispersant on the outside (nice semigloss black) wouldn't be a hard job to do, if someone wants to send one to me.

Here's a shot of the dry-film on some connecting rod bearings; by tonight, I should have lots more parts coated with a variety of products.

Randy--

Nice work. I now have your fingerprints scanned for future reference.

I'm sure the answer is obvious but I will nevertheless ask a question about which I have always wondered: Why were brake boosters added to later cars? There can't be that great a weight disparity between a roadster 3000 and a convertible?

Michael, My guess would be, Marketing. Everything was super assisted in the late '60s.