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Front Rotors Hot

Z

zkc27

New member
After replacing all 4 wheel bearings, front struts, and front lower control arms on my 98 GTP I'm having problems with my front rotors squealing and heating up big time. I did not replace the pads or the calipers during this repair session. I put in all new rotors and pads about a year and a half ago. I compressed the front caliper pistons and greased the caliper pins and the noise is still there. It is intermittent while driving. I did have a loose brake line (which I have tightened) last week and ran my fluid pretty low, but did not notice the squealing before the repairs.

One other thing that I've been wondering is my sway bar links were rusted so bad that when I replaced the front lower control arms, they broke. For now, I have a 5 or 6 inch 5/16 bolt with a deep well socket as a spacer between the sway bar and control arm bracket and one of those spongy spacers at each end of the bolt on each end of the sway bar. I do hear the sway bar popping and shifting every once in a while. I have sway bar links on order and they will be here tomorrow, but until then this squealing is driving me insane. Not sure how the sway bar links would affect the rotors, but felt I should mention just in case.

Bottom line, I'm wondering if my calipers need a rebuild or if there may be another culprit. Could I check the calipers by removing them from the rotor and pressing the brake as long as I have a block or something to prevent the piston from coming all the way out? I want to make sure they're going back in when I let off the brake. Also, the pads need to pull away from the rotors somehow when the brakes are released, right? I also want to make sure that my E-brake problems are unrelated to my front rotor problems. Any input is appreciated.
 


First thing I would do is lift the front end and just try to spin your wheels by hand, no need to remove anything to test it, you'll know for sure if they are. Have the car in neutral and the rear wheels chocked/e-brake on of course while you do this. If the wheels don't spin freely, then your calipers are likely locking up. Did you specifically use caliper pin grease when you greased your pins? If the grease isn't rated to a high enough temperature it will harden up pretty quickly and lock the calipers up. The clips that hold the pads sometimes get rusty too, I usually clean up the rust and put a tiny bit of anti-seize on them when reinstalling the pads.

Also, are they squealing all the time or only when braking? Because some pads will just make noise while braking, and rotors get very hot even under normal operating conditions. If they squeal even when you're off the brakes, and your wheels spun freely, then it may not be the brakes. There's normally a little bracket or "backing plate" of sorts that sits between the ball joint and the rotor, attached to the steering knuckle/wheel hub. You may have bent it to the point where it's rubbing on the back of your rotor, I did this accidentally last year and had a crazy scraping/rubbing noise until I realized and bent it back.

Don't concern yourself with the end links, they won't affect the brakes. If you wind up needing calipers, get new or refurbished ones, it won't be worth the time and money to rebuild them with how cheap they are. And as a tidbit, the way the caliper piston retracts when you let off the brakes is due to the design of the piston's inner seal (behind the dust boot you can actually see). It's a square cut seal that deforms and rolls slightly when the piston moves out, and then rolls back once pressure is released, pulling the piston very slightly back into the caliper.
 
who puts new rotors on with the old pads? thats a sin for real. if the rotors are not all cut up already, buy and install new pads asap.
 
Scottydoggs said:
who puts new rotors on with the old pads? thats a sin for real. if the rotors are not all cut up already, buy and install new pads asap.
Click to expand...
*Shamefully raises hand*

But I got 1 new pad on at least because my slide bolts were seized good and couldn't get 2 new pads over a new rotor.
 
Scottydoggs said:
who puts new rotors on with the old pads? thats a sin for real. if the rotors are not all cut up already, buy and install new pads asap.
Click to expand...

I did replace all the rotors and pads at the same time... about a year and a half ago. Sorry if that was unclear.

The squealing seems to happen moreso when turning but that could be coincidence. It happens sporadically for no apparent reason whether I'm on the brakes or not. Doesn't seem to get better or worse when I apply brakes after it starts squealing. I will check the free rotation of the front tires tomorrow or this weekend.

Also, thank you for explaining how the piston retracts. That has been bugging the heck out of me trying to figure out how that thing is supposed to go back in by itself. Much appreciated. Thanks for all the productive input guys.
 


While you hear the squealing noise, If hitting the brakes on and off do not affect the sound at all, I wouldn't doubt something else is the cause.
This was my issue, not the brakes.

 
Pads are good, cannot see anything wrong with them. Plenty of material left.

The video above sounds pretty darn close to what mine sounds like, except mine can happen going straight as well. Sometimes there's more of a rubbing noise mixed in too, but as I said that is pretty close. Any ideas on what his problem was?
 
That happened going straight too, only when braking. That ended up being my wheel bearing. Somehow it learned to play the violin.
 
Well all 4 of my wheel bearings are brand spanking new some I'm hoping I can rule that out. I had the front passenger side bearing on before I did both front control arms and the other 3 bearings this weekend, and I had no problems whatsoever with squealing before that. Another thing I thought of: I had a brain fart with my driver's side control arm off and the steering knuckle pretty loose. I tried to loosen the big spindle nut and something gave in the axle. I rotated the nut (or moreso the axle I guess) back to where it was, got everything secure and put a bar in the rotor to hold the axle like I'm supposed to and spun the nut off the right way. Haven't noticed any problems as far as that goes but it's been worrying me. Any way that could be related or does anyone have any ideas as to what may have popped in the axle? Hoping I didn't break anything I guess. I know I'm just full of questions... just trying to keep you guys on your toes.

Keep in mind my car has 220,000 miles on it so it's not like I'm screwing up a brand new car. Probably wouldn't be doing the work myself if the car was still worth anything significant so keep the scolding to a minimum and productive input as the focus please.
 
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zkc27 said:
More importantly, how the heck are you getting 37 mpg???
Click to expand...

It states 37 MPG highway, not average... and a lot of guys are getting 35 with decent tunes.

I'm running a lean AFR with open loop tuning to squeeze some more out of it.
 
Alright so the question for this thread was (or should have been): What would make the backs of my front rotors look like Edward Scissorshands made violent love to them? The correct answer was: The steering knuckle/wheel bearing bracket. Thanks for the suggestion nik12937. You win this day.
 
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