well first off, im about to get my clutch replaced and i highly doubt that my clutch has anything to do with the breaking problem, but i thought i'd let whoever reads this know the only other thing wrong with the car. Well its an 87 gxl, runs great, lately when i brake, hard or soft braking, the break pedal slowly needs to be pushed farther and farther, not all the way to the floor, but pretty close, i pump it to get the breaking power back. When im sitting a t stoplights or whatever, with my foot on the break the pedal slowly drops. I'm guessing master cylinder, i checked for air in the break lines, didnt see any bubbling or anything. And to be honest havent looked at the pads to see if they are really worn. but like i said im guessing master cylinder. Anyone else have this problem...or have any advice on what i could be or what i need to do. Any help is appreicated.


Thanks

 

No, the FC does not share a common reservior (unlike the BMW's and FD's), so I doubt your clutch problem has anything to do with your braking problem.

Are you losing fluid in the reservior?
If the fluid level is okay, it's most likely the brake master cylinder.


-Ted

 

I'm having the same problem.

If it turns out to be a faulty master cylinder - is it okay to buy a used good condition one versus a new one from Mazdatrix?

 

I would not buy a used one.
The problems with these things is that you have no idea what condition the used one is like.
If anything, buy a "seal kit" which allows you to replace all the soft seals inside.
This is highly dependent on how "clean" the bore is.
If the bore is pitted or rusted, then this rebuild will not work.
This is a cheap option if the main components of the brake master are still in good shape.
Last time I checked, this rebuild kit was like $30 - $40.


-Ted

 

Yes, if you're not losing fluid anywhere it means the master cyl is shot.

 

I would think twice about buying a used master cylinder. Remember, these are your brakes! If you don't want to pay OEM prices, look on the internet for a clone unit. You don't want a used unit to fail on you....isn't your car worth it? If you want to "rebuild" your cylinder, be sure to hone the cylinder properly to remove the pitting on the wall, as RETed stated. If the corrosion is too severe, trash it. Remember, it's the pitting that contributes to the wear and eventual failure of the seals.

 

I've had the same problem...

Before you assume its the master cylinder...can you hear a slight pssstt noise when pressing the brake?? does the brake pedal not stop but keep going down?

It may well be your brake booster has an air leak through the rubber, inside the can. Not too hard to imagine if your check valve is shot in your hose and allowing pressure in both ways as well as possible fuel to burn up inside your booster which will destroy the internals.....

 

dude i had the same promblem and i just went ahead and replaced my master and slave at the same time. i bought brand new ones off of ebay for i think around 80 shipped so check it out

 

Yes, either buy a new master cylinder, or repair the one you have (if in good cond as ted ststed). Don't just buy a used one, also check the the pads. My TII had a very similar problem and in my case bleeding all 4 wheels solved the problem and new pads made it even better.

 

Run down to Walmart, I bought myself a new brakemaster cylinder there. If it's the reservoir, grab a seal kit. But, it could also be one of your brake lines. The thing about used master cylinders, regardless of condition is that you don't have to piece of mind to know that no foreign debris has been through them.