smelly left front brake?

When I got home tonight I thought of the drive as a fitting end to a good weekend. But I had to go back out to the garage - and there was this faint acrid aroma in the air...followed my nose to left front wheel. Can a caliper seize on the rotor without causing steering problems? I know the pads 'were' in good shape, I replaced all the front end bushings several months ago and everything looked good. Any ideas on what did or could be happening?
Thanks
Paul

Do you know where your cat is? :)

What does it smell like? If the cali[er froze with the pad against the rotor, you'd have felt it in the steering. More likely something dripped on the caliper while it was hot.

The pistons don't have to really seize to get the same effect. They just have to keep a light pressure on and the length of time the pads stay in slightly heavier contact with the disc will do the trick. A "valving" flex line will do the same thing.

Stop using the car until you fix it.

Pull the discs and service the hub bearings. Replace the flex lines and pads and at least "exercise" the caliper pistons if not replace the seals. Don't split the calipers. You might want to skim the discs if you see a lot of blue metal. Flush ALL of the fluid out of the system front and back and do you bleeding routine.

Jack

Flex lines! Don't forget that they fail from the inside; the rubbery inside swells and, as Jack indicated, the swelling acts as a check valve. The pressure from the master cylinder forces hydrolic fluid past the swelling, but there isn't pressure sufficient to push the fluid back from the wheel. Hence, the pads stay in contact with the rotor.

The right front wheel on my car got almost smoking hot before the little light went on over my head.

Jim D

A couple of other "remote" possibilities could be a brake line or caliper leak allowing fluid to get on your pads, or perhaps your left hand caliper went through something that splashed onto the rotor or caliper and is causing the smell as it burns off.

I once had a friend call with a similar complaint and what we found was a plastic grocery bag that had been sucked up off the street and melted itself to his catalytic converter where it joins the exhaust down pipe. Nothing to do then but live with it and let it eventually burn off. If by some quirk, your left front caliper got something lodged on it or the rotor or between them, like a thin piece of similar plastic, this could generate a pretty good stink until it burned off, but not necessarily impair your steering such that you'd notice it.

Altho not very likely by themselves, the number of "unlikelys" that actuall do happen to folks does add up to at least a significant minority of problems folks have to deal with.

Basil, my wife says to tell you that is disgusting. But I do remember living in new England years ago that it was not all that uncommon...

Thanks for the info guys. I have some investigating to do after work. Its supposed to be wet and windy the rest of the week anyway.
Paul

paul74 Wrote:

As Jack noted you need to check the wheel bearing.

Or the wheel bearing seal. Most sold in the USA are single lip seals and are not as well protected from dust and dirt as those seals using a double lip. (the second lip which faces the outside towards the rotor is a dust shield). Dust and dirt will eventually grind away at the seal. If the seal leaks, centrifugal force sends the oily component of some greases onto the brake rotor surface. If this were true it would be pretty obvious once you have the wheel off as you will see the oily streaks radiating towards the outer part of the rotor on its back side (where you can't see it with the wheel on the car).

The left wheel does not rotate as easily as the right. I have removed it. There is a faint burn smell still. It seems to come from the caliper. I removed it. The pads certainly had more friction on the rotor than I expected but the caliper was not hard to remove. Once off the smell seemed to go with the caliper. The hub and rotor do not smell and the rotor is clean. There is no grease where it does not belong...
I removed the pads from the caliper and the pistons did not push out.
I replaced the bearings 6 months ago-the driver side had a shim but the passenger side, this one, did not.

Given my problem should I redo the bearings now or because the hub moves smoothly and the smell seems to be involving the caliper should I move on the brakes??

So brakes-new flex line, new pads, new seals??

Repack the bearings while it's apart but if there's no wear, don't bother replacing them. If you have more pad wear on the left than the right, the suspect is the flex line on the right! Expansion of the line moves the right piston less and you get more wear on the left. But you should feel that in the steering also. Your "faint burn smell" is hard to identify over the net - I'm not yet equipped with sniff-o-vision. But if it's typical burning brake smell, check the run-out on the rotor. A warped rotor will cause some uneven wear. Best of luck. Basil

You said that you repacked the wheel bearings and the left side had a shim and the right one didn't. Usually there are at least 2 or three adjustment shims on either side, unless the spacer was omitted. Did you tighten the axle nut down to 40 to 70 ft-lbs? Maybe your wheel bearings are too tight and binding.
Jack also may right about a collapsing hose. The calipers are usually pretty trouble free. Make sure you check everything. Brakes and wheel bearings should be at the top of any maintainence list. I had a front wheel bearing frag on me at 70mph with my dad in the car, my 65B in 1969. I thought I had a tire blow out at first. It could have been a lot worse, we didn't crash and the spindle was OK.