So my brake light came on the other day - checked the fluid and it was low. Filled it, and 2 days later the brake light comes on again. What the hell? All the brake lines look good, so I have no clue where it's going. I am assuming it's either the master cylinder or the ABS module - whichever one is more expensive is the most likely guess, I imagine.

Anyone run into this before?

 

Is it still full? If your in need of refilling it again in 2 days time there is definitely a leak somewhere. Assuming you visually checked all brake lines and fittings, it will be tricky to find. If your brake pedal is not spongy and the pedal doesn't go all the way down to the floor when braking, I would be looking for a leak in one of the brake caliper pistons. When the fluid leaks through a piston, it doesn't always leave a puddle or wetness. The centrifugal force of the wheel spinning disperses the fluid around the wheel well. Since it's not a lot of fluid coming out and it only happens when the brake pedal is applied, the leak is sometimes unnoticeable from the outside. Try going down a hill or somewhere where you would be putting the brake pedal down for a good minute. Then get out of the car, turn the front wheels and look at the inner part of the wheel rims. Do the same for the rears.

My 68 Camaro has this issue. It has factory 4 piston brake calipers and 1 one leaks slowly. The car brakes fine but I have to add fluid once a month.

Losing 4 to 6 ounces of fluid in a matter of days tells me this problem is not going to go away anytime soon.

Drive safe

 

If you're loosing brake fluid, but don't see any leaks, then pull the BMC (brake master cylinder) off of the brake vacuum booster. Get your flashlight and turkey baster to look for a pool of brake fluid at the bottom of the inside of the booster. If it's there, then you found your fluid leak, and you need a new BMC.

BTW: Do you have manual trans on this car? If so, then you need to ck that system too; master and slave cyl are most likely culprits.

 

good call gdog, That could very well be

 

no, unfortunately, it's an autotragic.

Still can't find any leaks....its starting to **** me off.

 

Um, did you look inside the booster..?

 

gdog: sure did - it isnt there.

 

Sorry, didn't mean to belabor the point; just wanted to make sure that was checked. So the seal around the BMC piston was nice and dry?

Well, it's gotta be going somewhere, unless you got a prankster lurking under your hood...

 

Have you pulled the ABS module? I've seen the hydraulic pump leak into the module on a few.

 

ES6T - ABS module is what's leaking...was looking under the hood and saw a couple drops fall off it...thought to myself "son of a bish" so how hard are they to change? Buying new is out of the question for me right now - my wife got laid off today and i just dropped 2 grand on dental work last week

 

they are not hard to change. see if midwest can help out
https://www.midwest-abs.com/850_ABS_Modules.php

 

It,s not the module that is leaking, it's the hydraulic pump. New ones are very costly and they come with a new module. You're much better off looking for a used one. You will likely need a module too because they are electronic and should not have any brake fluid in them.

Not too hard to change, remove the master cylinder, disconnect the brake lines and electrical connectors, unbolt it and remove it. After replacement, you'll probably spend a good while bleeding all the air out.

 

Well, I finally found my brake fluid leak, and it's coming off the hydraulic pump/TRACS assembly somewhere. I knew it'd be the most expensive part it could possibly be.

I plan on getting this at a junk yard - has anyone swapped one of these out before? Any tips would be great, thanks!

 

and it most definitely is not coming from the master cylinder or brake booster. I had a friend pump the brakes and could see it coming out from underneath the bottom part of the brake module there....i think the block on the bottom is the pressure switch? I have a GIANT puddle under the car now, and am driving it as little as possible. I'm having to refill the reservoir way too often - like every other day.

 

Glad you found the leak.

 

Midwest, it appears, only does 96 and up. I have a 94. Does anyone have a clue what's going to be compatible, other than another 94 turbo with tracs? Also, how often do these fail? I'd hate to swap everything only to find i had the same problem.

 

I'm pretty sure that's just the module, which is what most places rebuild. You need the whole pump.

 

I just went through this on the '94 850 last year. As has been said, the problem with the 94's is the pump, not the module. I found one in a California junk yard, but new I think they go for $1200 if you can find one.

What breaks? This is the maddening part. There are two cap bolts on the bottom whose heads rot allowing brake fluid to leak. See the picture. I can't find replacement bolts anywhere, but I suspect that this is the only problem.

If anyone knows where to find these bolts, I have an almost-working ABS pump that I would like to rehabilitate.

 

I found a pump assembly in the junk yard today that's even set up for tracs. I think I'll look onto finding bolts that plug the bottom though so i can fix the original and use it as a spare.

Xc...how hard a job was changing it out?

 

Tracs was a problem. I found lots of non-tracs pumps available, but had to go to the other side of the continent to get a tracs unit.

Changing it out wasn't too hard, but there wasn't a lot of extra room to work. If I remember correctly I took the master cylinder off to get more room. Be prepared to do a lot of flushing afterwards to get all the air out.