Removing the Brake Booster

[RRoller123]

Yep, I understand. I made the inquiries and was assured that this is a problem that occurred on a single lot a while back and has been fully resolved, both the 2 stud length issue, and the plunger adjustment range issue. I trust those 2 guys that they have fixed the problem... and I guess I could sincerely say that they are the most honest people I have ever dealt with. That being said, it is always wise to pay attention as this thing goes back in!

Pete

[micbrody]

near bottom of page letter "A" note: 1.035 to 1.925 mm

[RRoller123]

Perfect! I have that manual, and it is pretty much the best one out there for the stuff that it covers! Tonight we play with the new telescope, and maybe when it gets warm here the middle of next week, the Spider will get some needed attention.

I assume that the 4 mounting studs are the 2 unmarked features that point to the right, (They overlap so the ortho drawing only shows 2... ) and that they have to be unbolted from inside by the pedal linkage, and those 4 are all that hold the booster in?

Pete

[phaetn]

Heya guys.

About a week before the end of last season I noticed that the car started running rough when applying the brakes, nearly stalling if at idle.

There was a clear drop in RPM with brakes on vs. off. I figured a leaky brake booster; I therefore disconnected the booster hose and plugged it. It made for rock-hard brakes (no assist) but they still worked without affecting idle and it was only for a week. Then I drove it up a curb, but that's another story and nothing to do with the brakes...

A few days ago I went to look under the car to looking for suspension damage after it had been sitting for months and noticed fluid leaking dripping off the control arm. I checked the brake fluid reservoirs and one was empty and the other very low. They had been full when putting the car away.

The master cylinder was replaced last year so it should be good. Is there a seal I should replace on the booster or is it just easier to get a whole new booster from A/R? When replacing a seal is it just something easy on the exterior or does the whole booster need to be taken apart?

With thanks,
phaetn

[micbrody]

There shouldn't be any brake fluid connection to brake booster; I think the only way would be a faulty seal on master cylinder. So you said it was new, that makes it unlikely.
However: can you describe the reservoir levels better? There is a divider in reservoir that will keep a minimum amount of brake fluid to one the chambers of master cylinder if the other chamber system has a leak. Trace the hose that leads from the lower side of reservoir to master cylinder. That has to be the system that leaks. It can be anything from hose connections from reservoir to master cylinder ; the high pressure connections to that section of master cylinder; or just a bad, cracked master cylinder

[RRoller123]

Also, fluid leak can develop out of the back of the MS where it attaches to the Vacuum Booster. This is the situation I currently face. Same thing, brake fluid dripping down in the control arm, reservoirs emptying at a rapid rate. Lines appear ok.

[micbrody]

My understanding is that it is not normal for brake fluid leak into booster; you have to rebuild cylinder with new seals; or just purchase entire new one

[phaetn]

Also, fluid leak can develop out of the back of the MS where it attaches to the Vacuum Booster. This is the situation I currently face. Same thing, brake fluid dripping down in the control arm, reservoirs emptying at a rapid rate. Lines appear ok.

Yes, I was thinking along these lines. Is it ever possible that fluid backs into the booster itself somehow?

I know it developed a problem for sure because it was aspirating and affecting idle. So instead of the booster being airtight with a vacuum, air was seeping and affecting the intake manifold pressure. When I disconnected the hose and plugged it idle was fine. This means there was a problem before I ever noticed a fluid leak. I suppose it could be an external seal or worse, maybe the internal diaphragm. I don't look forward to splitting a booster to mess with the internals.

What compounds the issue is I really whacked the driver's side wheel hard into a curb a day before putting it away for the season in November. I totally trashed the front rim and tire, and slightly bent the rear rim's lip, too, but have had that fixed. It definitely applied a tremendous amount of force to the car. I haven't even looked at the shock tower, cross member, or steering linkages yet to ascertain damage. I just put it in the garage and closed the door leaving it to the spring. Now here we are. The hood fits ever-so-slightly differently on that side now and there's a small bow between the driver's door and the front quarter panel that is new; nothing is rubbing or scraping, but it's different (it wasn't there before because I had just had the car repainted the week before and would have noticed it). I wonder if force was somehow applied to the firewall (where the brake booster attaches) or if something else could have affected the master cylinder.

Anyhow, I have two different problems: the booster was leaking air before the impact; now brake fluid leaks (post-impact, but may be coincidental and not cause-and-effect).

I wonder it it's best to just get a new booster. I don't want to get too much money into this until I ascertain if the car is still good in case I have cracked something really, really seriously and I write off the car.

Cheers,
phaetn

[phaetn]

My understanding is that it is not normal for brake fluid leak into booster; you have to rebuild cylinder with new seals; or just purchase entire new one

Thanks - was composing my own reply while you were posting.

Cheers,
phaetn

[RRoller123]

I have heard that fluid can get inside the Booster, but I have no personal knowledge of that.

[NSFIAT]

I managed to get mine past the fuel rail (lots of wiggling) but the movement cracked the old rubber fuel lines. A happy accident as it's now resolved (and safer!), but something I wasn't prepared for at the time. I had to find the sweet spot with the push rod - I had it set to spec but the front driver side brake was still locking up after short drives. I thought it was a master cylinder issue at first.

[RRoller123]

I just finished swapping the Vac Booster and took a whole bunch of pictures, will post a procedure shortly, if I can get Photobucket to behave. (btw, I have noticed that PB has sped up lately, I wonder if they realize the tremendous mistake they made by artificially throttling down access?).
This was one of the worst jobs I have had to do on the car to date, and there are a few tricks that will help anyone else unfortunate enough to have to do this.

Pete

[AriK]

Funny you mentioned this Pete, i was having trouble with Photobucket earlier in the year when i was posting My City back in time. It was almost unusable for over a week. Then it somewhat improved just about the time everyone else was cursing that it was failing. It seems to be okay now.
Weird.

[RRoller123]

I bet the braintrust that runs the site got a report showing the drop in subscribers and traffic, and decided, like AOL wisely did decades ago, to drop the pay for service model, and stick with ads. Just hoping that it continues to work.

[phaetn]

I just finished swapping the Vac Booster and took a whole bunch of pictures, will post a procedure shortly, if I can get Photobucket to behave. (btw, I have noticed that PB has sped up lately, I wonder if they realize the tremendous mistake they made by artificially throttling down access?).
This was one of the worst jobs I have had to do on the car to date, and there are a few tricks that will help anyone else unfortunate enough to have to do this.

Pete

Ok - based on that I am taking it to a shop I like so they can do the work and I sip coffee.

Happily my brake fluid leaking resolved itself. I think it's likely a seal in the m/c that in below freezing weather contracts enough to let fluid past. Hasn't leaked in weeks since and I have been driving it often.

Right now I have the tube from the intake manifold plugged so the brake is rock-hard but works. Can't wait to get the new booster installed so I can go back to the old, proper pedal feel.

I might have the starter changed to one Dave is giving me when it's in the shop. Wonder if I should get a new old steering box I have done at the same time --- they're all in the same area.

Cheers,
phaetn