I've slowly been losing braking power in my FC over the past month or so. Its to the point now where I can't even lock up my shitty snow tires in the rain with the pedal to the floor. I bled the brakes and replaced the fluid but it didn't seem to help very much, and nothing is leaking. After searching, everything points to the master cylinder. The thing is, I replaced mine with a mazda reman about 3 years ago. Is it possible that this is still the cause? Any input would be appriciated. Its kinda unnerving not being able to stop like I'm used to in the FC.

 

kinda un-nerving and kinda EXTREMELY UNSAFE!!!

is there good pedal pressure? or does it slowly sink to the floor when you are really pushing it?

edit: are you losing fluid or no?

 

I'm not losing any fluid. The pedal doesn't sink to the floor when pushing it, it just seems to take alot of travel to have any sort of bite, and there is only about an inch of travel left once it does bite. I agree it is unsafe, and I'm trying to avoid driving because of it.

 

There is a brake pedal linkage adjustment in the FSM.

But, I suspect as you do, it's a bad MC.

 

when's the last time you checked your pads/rotors?

I would flush the brake fluid for starters - if there is no sinking in the pedal (I.e. you can STAND on the pedal and it doesn't sink) then your master is fine.

also, are the pad wearing un-even? perhaps you have a sticky caliper.....



there's no ABS on this car correct?

edit: I re-read your last post......is the brake pedal spongy? you could just need to bleed them......but I re-iterate, if the pedal DOES NOT SINK AT ALL then your master is fine

 

yes, you have a bad master cylinder

 

do you drive the car alot? letting a car sit will ruin a master cylinder as brake fluid is corrosive.

 

I checked the pads and rotors when I bled the brakes last week and they still had plenty of meat on them. The pedal is resonably firm, it just seems to run out of travel long before before maximum stopping power is achieved, and it doesn't like coming to a complete stop at all.

The car was driven nearly every day until recently.

I guess it is looking like I should go order a new MC...

 

Before you order a new MC. I would check to see if any of the brake piston is frozen. With any of the wheel or wheels lifted up (one or more is fine). Hold the brakes pedal (about half way or less) and have someone try to spin the wheel. Check to see if one wheel spins or spins easier then another. Sometimes the brake pistons will get frozen causing excessive pedal travel. Good luck!

 

If the pedal is not falling to the floor, you are talking about having extreme pedal effort and very little stopping power, it sounds as though the Booster could be to blame. Think about it, the booster is power assist for the brakes, without it you need a massive amount of effort/pressure, to exert any stopping force. Also, if you had a bad MC in the past, perhaps it was leaking? That leak could have been seeping into your booster the whole time, consequently eating away the diaphragm (sp?) in the booster, and now causing you problems. So even though you solved the leak, it may have already produced some secondary damage. First thing I would check would be the booster, make sure there are no leaks, and make sure any vacuum lines to it are producing the proper vaccuum.

 

That statement only appears to be partially true. Brake fluid is corrossive, and will eat away paint, etc. However, I don't think that would be the cause of failure if a car is sitting. More likely, the fluid will absorb moisture over time, which would cause corrosion within the system. Brake fluid is always sitting in the MC, whether you drive the car or not, and that fluid is designed to not eat away seals, to absorb some of the heat produced in braking, and to absorb moisture keeping corrosion inside the brake system down. It is when the fluid becomes saturated with moisture, you will have problems arise.

 

I had the same Issue. The vacuum hoses to my booster had rotted out.
Check yours.

I have a feeling that's your problem since you've got a reman master cylinder.

CHECK THE VACUUM HOSES TO YOU BOOSTER!

 

ok you guys read his msg wrong.

he has extreme travel, little effort until the pedal is almost to the ground.

easiest way to determine an internal MC leak is too pump the brakes if while pumping it the brakes start biting higher in the travel of the pedal then the MC is the blame.

if your booster wasn't working you'd have to stomp the pedal to make it move at all.

It sounds like a fluid leak at a line, but if you arent losing fluid that rules that out.

also reman master cylinders = so-so. ive seen ones fail in under a year, and others last long as hell. they're very touchy when being re-manned. a bit of dirt on the piston inside will cause premature failure.

kevin.

 

didn't I ask you something about the brake pedal sinking?hehehe

you need a master

 

brake booster fa'sho. see if revving your engine affects where the brakes 'bite'. try this in a parking lot away from people. if it does its probably a vaccuum leak to the booster or the booster itself.

 

YES!! After re-reading my posts I was a bit unclear before, but this is what I was trying to say and not sure how to.

 

Lift your wheels up and press the brake pedal about half way. And have someone try to spin each wheel. Try you keep the brake pedal pressure the same for all of the wheels. Sometimes the brake piston will get frozen inside the caliper causing excessive pedal travel. We have a car at work that did the same thing. The funny thing is that we replace the MC on that car a year before. Good luck!