brake problems

[jmartinz32]

i am an old 300zx owner now with an sx. I am experiencing things never seen in my z. most importantly is a brake situation. in the first few miles of a drive the brakes seem fine, after a while i can feel increased heat coming from the trans. (console) area, and if i use the brakes they are sticking closed. this happens even if i do not use the brake at all. what i mean is, if i travel from a cold start down the interstate, as the car heats up, the brakes tighten up. (as if riding the pedal) if i come to a rolling stop the brakes are closed to the point that you can't even push the car. all four rims are hot. when the car sits long enough afterwards the brakes release and the story starts all over. this is happening to ALL wheels. i have replaced the master cyl. i am new to the forum and i have search for answers to this problem in the archives. (Thanks for helping me with other problems from your library!) i am getting "advice" from other sources as well. so, to sum up my situation: >could it be calipers? why all four and not just one? or two? >brake hoses? >could some idiot have used a foreign fluid in the system? (like transmission fluid) >it has aftermarket rims, could the caliper be possibly rubbing on the rim and heating up? this might explain all four rims being hot and all four brakes sticking >i need a fan clutch- could the engine compartment be heating up, causing the brake fluid to expand?????(what kindda question is this???) > shims? > it does not have anti - lock brakes, if that matters on the prognosis

O.K. there it is-i have already spent the 60 bucks plus time on the master cyl. i didn't need. i would appreciate some feedback on this before i throw any more money at it.

Thanking you in advance for your time------Mike

[MojoMan]

If the last person that did a brake job on the car didn't know they were supposed to screw the pistons in and not use a c-clamp then all of your calipers are sticking. If your calipers were rubbing you would both hear and feel it. This is a dangerous situation you are in and I would A) take it to a shop or even tow it or B) start running down the list of things to check, such as are they the right brake pads? How new are the pads and rotors? You are definitly putting a lot of extra stress on the drivetrain so dont wait to fix it any longer. If you feel the brake fluid that is in there is old or not the correct one then bleed the old out of the systen and put new in. If you have replaced the master cyl. there are only so many things it could be. The calipers could be warped as well. How many miles are on the car. The calipers might need to be rebuilt. Like I stated above if your brakes were done wrong on previous brake jobs your calipers are bad.

[ricebike]

oor, u got a defective master cyl from the aftermarket manufacturer... got lifetime warranty on it w/ receipt?

my raybestos master cyl failed after about a year of use...so that may be one of the causes...

unbolt the sliding caliper pins and regrease all of them; drive around till operatin temp... they start binding up on you again... start thinking about caliper seals/rusted o' seizing pistons.

If the rear pistons are seized up d/t improper pushing & turning the pistons clockwise for the new rear brake pads, then the system has to compensate & use the fronts more...which will tax it to the point of brake fade/glazed pads/rotors...etc.

a good sign that the pins need regreasing o' rusting pistons are the inboard brake pads are wearing out alot faster than the outer ones...

i don't think it's the hoses unless you have a mushy pedal, which also indicates air in the system as well...

"could some idiot have used a foreign fluid in the system? (like transmission fluid)"--- If that were the case, that would suck @$$; then you'll have to replace everything, including the rebuilt aftermarket master cyl u just got.

PS, bud is your car 89-90 sohc engine? If so, I can give you a brand new fan clutch from Hayden FREE +shipping... but, lemme tell u, they suck @$$ as well... I changed mine out 3X in the past 3 years. others would pay more for the OEM or get a junkyard unit or switch to an electrical fan.

Ya, higher underhood temps usually not good for the brake/clutch fluids; umm but they have high boiling points already & since u had a master cyl replacement this shouldn't be the case ( did u BENCH BLEED the cyl before the install?)

I got me a minor exhaust manifold leak BUT I do flush/change out my brake/clutch fluid every 2 years anyways :P

Keep us posted; I wanna learn from your experience.

[jmartinz32]

thanks guys- the car is in storage so i will not be putting any further stress on it- i will get it into the shop with the list of scenarios for the problem- i recently purchased the car and do not know the history on it- it has 200k on it- still in good shape for a '91- other problems to be addressed later- small stuff not a big deal- i do have a question about this forum thing, why under my name does it say "driving mom's car"- my mom is 72 and drives a corolla-why would i do something like that? "o what a feeling???"---can this be changed, or am i stuck with it?? i will keep you informed on the progress--thanks- mike

[drjohn]

You might check the clevis pin under the dash at the brake pedal. This pin should be loose and spinning free with the pedal fully up. If not adjusted properly this will put equal pressure on all 4 brake calipers and cause the brakes to bind. To adjust loosen the nut at the booster rod and turn the rod in or out to get the needed free play.

[GroundZero]

i do have a question about this forum thing, why under my name does it say "driving mom's car"- my mom is 72 and drives a corolla-why would i do something like that? "o what a feeling???"---can this be changed, or am i stuck with it?? i will keep you informed on the progress--thanks- mike

it's just a rating based on the amount of posts you've written, soon you'll have hub caps

[yellow_jacket]

Your most likely culprit is stuck slide pins or clogged lines.

Slide pins- very easy, make sure they slide freely.

clogged lines-Have someone step on the brakes with the wheels off. Check to see if your calipers release. If they don't, Then check to see why. Is it because you still have a ton of fluid pressure? If it is fluid pressure, have someone step on the brakes and release the pedal. Then crack the line open until you find a spot with no pressure(you will have to step on the pedal again each time you crack the line open.

[bendychicken]

Ummm, what would happen if you did use a C-clamp on the back pistons? I think I did that when I put my back rotors on. Am I in trouble now??:thinker

[RatedR]

I'm experiencing the exact same thing. I noticed that before the car heats up, it feels like there's air in the system. Then it builds up and gets REAL stiff and locks up. It locks up to the point the the car wont roll back on a hill. I noticed that if I scoop the pedal from underneath with my foot, then it'll release it. Would this be the same problem you're having???? Also, if you find an answer, please post. Much appreciated~!

-R