Brake issue, new hardware but car brakes itself

[Edwin562]

Hey guys, i looked around(google) and seems i havent seen anyone with the same issue im encountering. well at first it started that the car felt slugish like if the brakes were being applied... so i inspected my brakes, and found out my pads had un even wear,indicated caliper failure. so when i took caliper off, the piston wouldnt go back in,indicated piston sticking.... nevermore i bought remafg calipers with new pads, hardware the whole enchilada.... even brake lines...... i bleed the system twice to ensure myself no air is in the system..... after a week or so driving fine with no issue.... problem is coming back..... now it only happens when car is warm.... at cold car rolls fine,, but once car is hot... brakes start applying without me touching brake pedal. also at some times, pedal feel stupid stiff..... im stuck....

for those who are babies and dont want to read...

-brakes apply without me pressing on brake pedal..

-new caliper,pads,hardware,rotor,brakeline etc..

-brakes properly bleed...

-s13 hatch without ABS

-issue only happens with car reaches operating temp.

Edit: its a single pot OEM Caliper.



help..... plz school me on brakes....

[codyace]

Master Cylinder issue? We've had cars come through the shop with odd draggin issues to find that being the culprit. Another thing to check is the rod between the MC and the Booster (if you haven't touched it, it shouldn't be an issue). Are you sure it's not an issue where the other side is hanging now?

Also when you say you've bled the system, did you flush the ENTIRE system, or just bleed it. Sometimes dirty/old/mangy fluid can cause syptoms like this.

Another thing to consider is that uneven brake wear doesn't alway smean the caliper is shot...you can usually clean the slider pins and it will work fine. This doesn't always apply but something to keep in mind.

[Edwin562]

Master Cylinder issue? We've had cars come through the shop with odd draggin issues to find that being the culprit. Another thing to check is the rod between the MC and the Booster (if you haven't touched it, it shouldn't be an issue). Are you sure it's not an issue where the other side is hanging now?
anything from the pedal to MC, i havent touched it.

Also when you say you've bled the system, did you flush the ENTIRE system, or just bleed it. Sometimes dirty/old/mangy fluid can cause syptoms like this.
full Flush/bled, since i was changing my front brakes, i took the advantage of the time and redo all my brakes, so yes

Another thing to consider is that uneven brake wear doesn't alway smean the caliper is shot...you can usually clean the slider pins and it will work fine. This doesn't always apply but something to keep in mind. funny story,
when i took it in to napa for replacement, they check it out and told me how was i getting around with brakes like these.. lol
they "claim" piston was seized inside the chamber... which i kinda dont beleive.


anyways, thank you sir for you input, really appreciate it... if u were near i would invite you to a beer.. :)

[codyace]

Hehe, one Westy 8 please ;)

It's certainly worth checking the MC and the sort. A failed power booster would provide a super hard pedal, but wouldn't make or cause them to drag and or sieze up.

Having had a full flush then you obviously got all of the grimey old junk out too...you'd be surprized how many just bleed a new caliper and have it seize again.

There is no doubt a piston could seize in a caliper...however that's much more common on the rear of these cars. Front ones are possible though, just not as common. I'd drive around until it starts to brake itself, and then see if it's possibly the other side that is now seizing up/locked.

[S14DB]

Did you replace or reuse the piston slider pins?

[codyace]

Did you replace or reuse the piston slider pins?

curious here...usually you can take the slides out and clean/repolish them without issue... should I not be doing that?

[curbhuggerrps13]

That's fine my old 89 did so I got a new master cylinder and brake booster and top the fluids and then bleed any air.

[Edwin562]

Hehe, one Westy 8 please ;)

It's certainly worth checking the MC and the sort. A failed power booster would provide a super hard pedal, but wouldn't make or cause them to drag and or sieze up.

Having had a full flush then you obviously got all of the grimey old junk out too...you'd be surprized how many just bleed a new caliper and have it seize again.

There is no doubt a piston could seize in a caliper...however that's much more common on the rear of these cars. Front ones are possible though, just not as common. I'd drive around until it starts to brake itself, and then see if it's possibly the other side that is now seizing up/locked.
when car really starts to brake hard.... like suddenly... i jack the car up and spin the wheel, fronts are very hard to turn.... the rears, spin freely... so i know its my front calipers.... so with that said, could it be a proportional valve? do s13 have proportional valves in the front??

That's fine my old 89 did so I got a new master cylinder and brake booster and top the fluids and then bleed any air.

so change everything?? i might of well wait til i get my z32 brakes... REDO everything.....

[Edwin562]

Did you replace or reuse the piston slider pins?

Caliper hardware is all new.... everything.... i didnt use anything from my old front calipers..

[S14DB]

curious here...usually you can take the slides out and clean/repolish them without issue... should I not be doing that?

As long as they are straight and have no gouges or uneven wear you should be fine with cleaning and re-greasing.

If they have some dull sections or gouges and are no longer chromed I would replace them as they are only $1.50
Caliper hardware is all new.... everything.... i didnt use anything from my old front calipers..
Good, most kits come with the new sliders these days.


when car really starts to brake hard.... like suddenly... i jack the car up and spin the wheel, fronts are very hard to turn.... the rears, spin freely... so i know its my front calipers.... so with that said, could it be a proportional valve? do s13 have proportional valves in the front??

Sounds like the seals/piston in the MC are going. The proportioning valve is in the MC.

[Edwin562]

i pretty much thought so, well i will get it replaced asap... thanks dude i really appreciate your help...

[curbhuggerrps13]

well upgrade to the z32 if ur gonna go 2 pot z32 brakes. Very affordable upgrades