this has been a problem since converting my 82 brake system over to all 1984 brakes "swapped for disc rear" now everything was swapped from my 84 trans am into this 82 every brake line, master cylinder, proportioning valve. The 84 never lost fluid & neither did the 82. Also I retained the stock 82's brake booster though.

I have looked under the car everywhere. I never have seen fluid drippage on the rotors or the rims nor have I seen and on the ground.

So where is the fluid going? Master cylinder needs to be filled 2-3 times a week. The rear portion of the master cylinder always goes empty. And the front portion stops at half full (due to the slot in the master cylinder) and if the front portion has fluid left why does the car have no brakes? I always thought each portion was for the front or back brakes.

Also since doing the brakes I know the rear brakes are working yet thats all that really feels like is working.

So why am I not seeing fluid anywhere?

 

The rear chamber on the master cylinder is for the front brakes. The front chamber on the master cylinder is for the rear brakes. Why it is designed that way, I have no idea.

I am guessing you have weak or non existant braking power on your back brakes. From what I have been reading in the threads the back disk brakes need to have the emergency brake adjusted in order for them to work correctly.

As to why you are not seeing any leaks, well, that is a tough one. The front brakes are pretty straight forward. Here is what I would do.

Get out some newspapers and lay them down on your driveway, so the the newpapers will be under the front tires and also under the area of the car inbetween the front tires.

Drive the car onto the papers.

Fill up the master cylinder and put the cap back on.

Get in and mash the heck out of your brake pedal. Think "Panic Stop"

Do this repeatedly.

Eventially there should be a puddle forming.

I am guessing whatever leak you have is a small one. Doing the "Panic Stop" pedal mash should put as much pressure as possible on the braking system, causing whatever part is "kinda leaking" to leak with a little more volume.

Good luck!

dzimmerm

 

the backs seem to work ok. but when fluid level drops then they dont work very good. Could my brake booster be sucking fluid out of the master cylinder

 

If your brake fluid was being sucked out of your master cylinder by the booster then you should find evidence of brake fluid inside the vacuum line going from the booster to the intake manifold.

Such a condition would indicate a leaky master cylinder.

I should warn you that between 1982 and 1984 birds fittings went from SAE to metric, I am not sure if you could or would even want to try using the old 82 master cylinder due to this. Replacement rebuilt master cylinders are pretty cheap. I would try that if you suspect a leaky master cylinder.

I am guessing you have already tryed to get the leak to show by the methods I mentioned.

One other thing, if the brake lines for the front are running near or touching any part of the exhaust system there is a chance you are vaporizing your brake fluid.

Good luck!

dzimmerm

 

It would not disappear. It sounds to me like you still have alot of air in the lines and the system needs pressure bleeding. Your calipers could have retained air pockets inside them when you first bled them and you got some pedal pressure for a little while, then air escaped back up the lines towards the master cylinder. You need to bleed them from the closest wheel to the furthest wheel to make sure air in the shorter lines does not enter the longer lines when bled. It would be easy to bleed the long lines and suck a bit of air from a shorter line into them close to the master cylinder. I actually gravity bleed all of them first for a minute filling the master cylinder then cap them and start the bleeding from the shortestwheel line to the longest. This helps prefill the starts of each line and lessens the chance of sucking air back from one to another line.

Hope this helps

 

I initially though it could be the master cylinder however that was replaced about a month ago and he car still did the same thing. even with the old master cylinder I did check for signs of fluid in the booster and vacumn line but didn't see any.

The brakes have been bled and fluid has steadily come out of every caliper through the bleeder valve.

None of my brake lines are remotely close to my exhaust system especially near the drivers side manifold. I made sure of that when I put the newer lines in the car.

I do know the rear calipers are working based on with rear wheels in air brake applied engine dies when releasing the clutch. However I suppose only 1 caliper could really be working since the car has posi. I had to replace 1 rear caliper since it's piston was siezed. I am going to look and see if the other rear caliper is siezed and thats where the leak is later today.

Since the rear portion of the master cyl. always goes empty I will check everything real good that has to do with the rear brakes then.

I do see alot of brake dust on my front rims and a little on the rears so I am assuming the brakes are working but this leaK is just keeping air in the system.

 

OOOOPS I just re-read that the rear portion on the mater is for the front brakes.

Guess I will really look at the front lines today. maybe it could be that line that runs under the motor and the fluid is spraying on the Y-pipe and thats why I never see a leak.

 

Well, the problem was fixed ..... It was he front brake line that runs under the engine. and yes it was tough to change ... however brakes seem to be working great now but I sill need to bleed them. been driving the car for awhile now and it doesn't seem to be losing and fluid whatsoever. the answer to the question why no brake fluid was ever seen ... the crossmember had a fair share of crud built up on so my guess is it absorbed most of the brake fluid or the exhuast was burning it of the "Y" pipe had stains as if something was being burnt.

anyways thanks guys for your help

 

Thanks for the conclusion to the problem. Its nice to see when a person askes a question and people try and help with responses that the original poster comes back in and gives a final summary as to what the actual problem was- thats rarely seen around here. It would be far better for other people experiencing problems to be able to search such topics and actually see a final outcome so they are more informed where to look also.Thank you.

 

Brake fluid does burn off if it hits hot exhaust pipes. I had this problem on another car, the brake line was old and had a pinhole in the metal and it was spraying straight to the headers (how convienient, eh?) about 3" from the port and there was NO evidence aside of the tiny whiff of smoke when applying the brakes... thats how I knew there was a problem, I saw the smoke one day.

 

Well I had the brakes professionally bled using one of those pressure type bleeders ..... awsome difference in the cars braking now I forgot to mention before I used to smell my brakes before as well and the car would pulled pretty good to the left under braking .... so far so good level in the resovoir remains the same and and not as much brake dust appears on the left front wheel .... mechanic verified all calipers were working normally and now the brakes stop the car with ease and it also stops perfectly straight .... wish it had abs though .... Just a couple minor problems to fix now and I am going to sell my car and focus on my corvette.

hanks again everyone