z driver 88t

Based on symptoms, I'm pretty sure my brake booster has started leaking and I'm planning for the job. US model 16V.

I found Stan's write-up here:

https://rennlist.com/forums/928-foru...e-booster.html

Which seems pretty straight forward - although as most have described, I expect it to be a pain in the ***.

One question - when you remove the master cylinder from the booster, is there enough clearance to pull the booster with the master cylinder and reservoir still hooked up to the brake lines and just pushed out of the way? Or is it necessary to remove it completely from the engine compartment completely? I am assuming the latter, but would love to hear otherwise. Thanks.

hacker-pschorr

On my 80 there was no way the booster was coming out with the master still there. The booster takes up a lot of room and "just" squeezes out of the engine bay.

It really wasn't a big deal, when the job was all done I was very surprised how quickly it went. The most time consuming part of the job was having to jack up the car to bleed the brakes.

At least with mine, when the brake pedal was to the floor the rod you "clamp" was not all the way out. Maybe still had 1/8" to go and that small bit made all the difference in the world. I was struggling to wiggle the booster out of the car, took a screw driver and pried behind the clamp holding the rod. Sure enough, it moved ever so slightly more and with that little bit moved, the booster came right out with out a fuss.

I used a small hose clamp to hold the rod, actually two just to be safe.

My problem ended up not being the booster itself, but the seal between the brake master and the booster. I put a bit of Dow Corning DC 111 on the new seal. If you don't have any, most auto parts stores carry Sil-Glyde, I know a few shops that swear by the stuff for any application others would use DC111.

Side note, pre-spray all the brake fittings with PB Blaster or some other equivalent. You may also need a very short wrench to reach the back brake line that is between the master and the fender. If you don't have line wrenches, this is a good job to go buy the sizes you need.

Stuff as many rags as you can below the job to catch any brake fluid. Even after sucking out all the fluid from the reservoir, quite a bit spilled down.

I ended up removing the short brake lines that go from the master to the distribution blocks below it. Not sure that was necessary but I didn't like the pressure I was putting on those lines trying to wiggle out the booster.


When re-fitting all the brake lines, connect up everything loose before tightening anything down - this includes the two bolts holding the master to the booster.
The brake hard lines may need a bit of "wiggle room" when going back in and you don't want to strip anything.

Mrmerlin

you have to remove the master first then remove the booster.
usually you replace the booster and MC as a set.
make sure not to scratch the seating surfaces of the booster if it leaks,
then you will not have good brakes

z driver 88t

I was afraid you were going to recommend that. I hate turning a $300 job into a $500 job, but it may make the most sense, especially if I can get another 30 years out of the next set.

Thanks for the input.

Mrmerlin

while your at it get a set of stainless steel flex lines and a liter of ATE Gold fluid Roger sells it.
use EBC super red stuff pads, result very good brakes

hacker-pschorr

Replacing both at the same time may be best practice, I didn't since my only issue was a leaking booster. I fail to see how this negatively effects the master.

If the master fails and fills the booster with fluid that's a different story.

If both are to be addressed, I would opt for a rebuild via White Post versus new:
http://www.whitepost.com/