Hot Front Left Rotor

Sounds like a stuck caliper. Is it pulling that way..?

1998 Toyota Corolla, 100,000 miles, Oil Changed Recently, Muffer Hanger Recently Changed, Brakes Changed (pads & rotors) in December.

The vehicle does not pull left. I'm not sure if smells like burn> Please tell us the basic details of your vehicle: =A0year, make, model,

It does not seem to pull in that direction.

I'd have a look at it. I had a stuck caliper and figured it might loosen up, so I drove the car. Seven miles from home I had quite the smoke show. I would drive 3 miles and stop for 20 minutes.

It may not be too serious, and depending on your mechanical skills and the fact tomorrow's Sunday, it may not be a crisis.

Jack the offending wheel and put the car on a stand. Remove the wheel and then the caliper. You probably don't have to remove the caliper from the wheel. Get some emory cloth and a Dremel if you have one.

You want to remove the caliper and then the boot from the sliding pin on the caliper, probably the top. I bet you'll see a lot of rust in the bore. With the emory cloth wrapped around a drill bit or a dowel, 'hone' the bore out until it's nice and smooth. Grease with some Sil-Glide and reinstall the boot. Give the sliding pin a good polishing with the emory cloth and give it a greasing with Sil-Glide, and reassemble. I did this with two calpiers on my Supra and one on a Grand Voyager and they're still fine. (Well, the Supra. I broke some bolts in the engine of the Gr V'ger, and it's long since returned to scrap metal, hasn't it?!)

Unless the repair shop is square, "I'm afraid you're going to need a new caliper. It's $92.50." (They're about $50 rebuilt...)

This is an MR2 Rear Caliper, but the fronts are similar. Just about dead center of the picture are the glide pins with the boots nearby.

Please tell us the basic details of your vehicle: year, make, model, odometer reading, recent service conditions, and, repair history.

A hot brake may be a dragging brake, which is a concern. Does the vehicle pull to the left on a sharp stop? Is the smell you report one of burning brake friction material? You may have smelled this in the past when a heavy truck stoped suddenly near you.

Did you replace rotors, pads or calipers recently? Was the vehicle parked for an extended period?

Good luck,

Jack

FWIW it could be the hose too in addition to the stuck caliper theory. I had this happen personally on the left front wheel of a '92 Dodge Dynasty. The metal bracket that attached the middle of the hose to the back of the strut rusted on the inside and since steel expands as it rusts it constricted the hose. The pressure of applying the brakes was enough to force fluid past the constricted section but once in the caliper the fluid pressure couldn't get back out and as a result the brake stayed applied. In my case the combination of the constriction reducing the pressure to that side and the brake getting so hot that it started to fade the car actually pulled to the right when braking. Mine was so bad that the whole rim was too hot to touch after driving just a few city blocks. I had to replace both hoses, both sets of pads, both rotors, and the caliper on the affected side. I did both rotors as the one on the affected side got so hot that it cracked in 2 places and I felt that the other might as well be replaced too since I got new pads. The caliper I replaced because the heat cooked it and the phenolic piston was starting to crumble.

IOW I wouldn't drive it much till it is fixed as if your rotor cracks it can break apart and either have pieces jam in there and lock up the wheel or rip the pads out and result in no braking from that side. Either situation would be extremely dangerous and could cause you to lose control and crash.

I read some of the other posts and your responses. Since you don't have a noticeable pull, I doubt if the caliper is binding - that is, the piston is probably not stuck.

The most likely cause of one side rotor being hotter than the other side is that the caliper slide is binding, which a good cleaning and re-lubing the caliper slides may cure. Another possible cause is that the friction material have worn down to metal and you have metal-to-metal contact.

In either case, I would have the brakes looked at by a competent shop.

Where in ME are you?

Although I am a happy Corolla owner and do all my own service, I don't know for sure what is wrong with your car. The service conditions seem not abnormal. I would defer to a more experienced group member's analysis of your car's condition, for example Ray O.

It is remotely possible that you have a caliper binding - I am not able to tell from the information, especially as it is not pulling left on braking. There is a driveway test that you can perform to detect a dragging caliper, which is noted below. You may have a bearing going - is there any noise associated with this wheel?

Disc brake pistons are pressure-applied by many tons of force. The pistons are 'sprung back' -- released -- by the recoil of the rubber piston ring. It has a square cross-section, and sits in a square groove in the wall of the cylinder. When brakes are applied, the rubber is deflected forward as the piston is pressed along over it, much like a cardboard box deforming from a square to a parallelogram. Although applying hydraulic force is great, the releasing force is slight. There is no 'return spring' to re-set the piston. There is a tiny boundary layer of air over the surface of the rotor which also serves to separare the rotor and pads once hydraulic pressure is released.

When a caliper binds or seizes, the rubber piston ring reaction is not strong enough to move the piston back by recoil. As a result the pad stays in contact with the rotor, although not under force of braking pressure. The friction causes heat, burning and an associated odor. If friction heating is strong enough, the pad will come unglued from its metal backing plate. Interestingly, if rotors are badly rusted like something out of the mud at the wreckers, they can cook your pads right off in a couple of miles. The little grey slab of friction material will be totally free.

Checking for a dragging brake: (Observe all safety procedures to raise the vehicle. Loosen lug nuts with wheel on ground first. Of course, you will want to block all 3 other wheels both directions before jacking up the car so it can't swivel off the jack).

Tip: If you drive up onto a couple of pieces of 2 X 6 laid flat you may be able to fit a piston jack under the control arm, so that you won't have to hoist the vehicle very high.

If a brake is dragging, the wheel will not spin freely when the car is jacked up. Apply the brakes firmly, then release, then spin the wheel by hand. Do you feel resistance, or does it spin freely? (You may need to put the car in neutral to free the drive train).

If you remove the wheel, lever the pads back away from the rotor, then (without touching the brakes) replace the wheel and it spins freely, the conclusion would be that the brake is dragging. Be careful not to harm the pads or rotor when levering the pads away from the rotor.

To confirm, you would again apply the brakes firmly, maybe pumping a couple of times to ensure that the piston is fully extended. Then release the service brake pedal and check the resistance to spin. There will be resistance if the brake is dragging. If in doubt about the amount of resistance, compare with the other side wheel.

Good luck,

Jack

1998 Toyota Corolla, 100,000 miles, Oil Changed Recently, Muffer Hanger Recently Changed, Brakes Changed (pads & rotors) in December.

The vehicle does not pull left. I'm not sure if smells like burning brake friction material. Also, the vehicle is parked during the week and driven on the weekends typically.

"C Yohman" ...

From reading this whole thread I am betting that something is causing the pad to drag on the rotor. This probably is due to the piston not releasing fully. One possible cause of this that I have not seen yet would be the flexible brake hose getting gummed up or clogged inside. This might allow brake fluid to pass toward the brakes when the pedal is pressed pushing high pressure toward the brakes, but not allow the brake fluid to move back and allow the brakes to release fully.

Based upon what I see as your confidence level in tackling this on your own, I would suggest that you take it to a nearby shop that you trust. You now know what the possibilities are from the good opinions here, and can talk with some confidence to the shop guy.

Good luck and definitely come back and tell us what happens. Tomes

You have a caliper sticking or something else sticking. Take it to a mechanic or dealer to get it fixed.

jeff

******** Of the Toyota dealers near you, I know the one in Saco the best, and they are very good.

Good luck!

Re: Hot Front Left Rotor Group: alt.autos.toyota Date: Sun, Apr 6, 2008, 3:55am (EDT+4) From: snipped-for-privacy@merrychristmasi.com (Daniel=A0Who=A0Wants=A0to=A0Know) FWIW it could be the hose too in addition to the stuck caliper theory. I had this happen personally on the left front wheel of a '92 Dodge Dynasty. The metal bracket that attached the middle of the hose to the back of the strut rusted on the inside and since steel expands as it rusts it constricted the hose. The pressure of applying the brakes was enough to force fluid past the constricted section but once in the caliper the fluid pressure couldn't get back out and as a result the brake stayed applied. In my case the combination of the constriction reducing the pressure to that side and the brake getting so hot that it started to fade the car actually pulled to the right when braking. Mine was so bad that the whole rim was too hot to touch after driving just a few city blocks. I had to replace both hoses, both sets of pads, both rotors, and the caliper on the affected side. I did both rotors as the one on the affected side got so hot that it cracked in 2 places and I felt that the other might as well be replaced too since I got new pads. The caliper I replaced because the heat cooked it and the phenolic piston was starting to crumble. IOW I wouldn't drive it much till it is fixed as if your rotor cracks it can break apart and either have pieces jam in there and lock up the wheel or rip the pads out and result in no braking from that side. Either situation would be extremely dangerous and could cause you to lose control and crash.

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Chrystler products are notorious for their stuck caliper pistons especially if you let them sit for awhile. But any older car can have this as the piston seals age. In the yee old days we'd rebuild a caliper (starter motors 2). Is anything (under 300 dollars) rebuilt anymore..?

Chrystler products are notorious for their stuck caliper pistons especially if you let them sit for awhile. But any older car can have this as the piston seals age. In the yee old days we'd rebuild a caliper (starter motors 2). Is anything (under 300 dollars) rebuilt anymore..?

Mine wasn't a stuck piston as when I opened the bleeder screw no fluid dripped out. Usually when you open a bleeder or disconnect a hose from a caliper fluid will run out at a rate of about 1 drip per second due to gravity but in my case it didn't and that is how I knew it was the hose.