Is my memory correct when it tells me that car brake pads have a little noisemaker built into them that starts squealing (by dragging on the disc) when it’s time to replace them?
My car’s right front wheel is intermittently making a horrendous racket that sounds, unsurprisingly, like something small and thin dragging on a spinning chunk of metal. Since it only makes this noise when I’m in motion, and it stops when I apply the brakes, am I safe in assuming that it’s the “noisemaker” I’m hearing, and not the metal-on-metal contact that would occur were my brake pad completely gone? It seems to me that any screeching caused by a completely gone brake pad would start when I apply the brakes, not stop.
While I intend to have the problem repaired ASAP, I’m asking because I took my car to Les Schwab during the last week of May to have a front axle replaced (a problem I was already aware of, having discovered a torn boot while changing out my studded tires). At the time I assumed the squealing was the result of lost wheel bearing grease. I was only hearing the squealing occasionally and decided to get it fixed before it got any worse. While I had the car at Les Schwab I asked them to check the brakes while they were at it.
They said my brakes were fine - that the pads still had some life in them. They did however give me an estimate on a brake job: ~$75 for a standard brake job, or ~$300 if they needed to grind the discs. I assume I would only need the second option if a completely worn out brake pad was causing metal-on-metal contact and putting grooves in the discs (is this correct?), so naturally I want to get this fixed before it gets to that point.
I didn’t hear any squealing for two days after having the axle replaced, but then it started up again, which suggested it was the brakes, not the axle. While initially I only heard it now and then, now I’m hearing it almost constantly. I’m not having any trouble stopping the car.
My car is a 1989 Honda Accord.
Some, but not all, brake pads have wear indicators such as you describe. Usually, the indicator makes its noise when the brakes are applied, but sometimes it will do as yours does. Generally the indicator can touch the disc when the pads are about 85% worn.
Worn-through pads typically make a grinding sound when applied. Squeaks and squeals can be caused by other things - they sometimes indicate a problem and sometimes are just an annoyance noise. Nevertheless, it certainly makes sense to have the brakes inspected, especially when the noise has gotten worse, as yours has.
Most car manufacturers say to machine or replace the rotors only if there’s a specific problem - warpage, deep scores, not enough thickness, etc. If cheap pads are used, however, they may make noise (often squealing) unless the rotors are also serviced.
Honda’s are pretty easy brakes to work on yourself if you’re so inclined. They might have a “glaze” on them for want of a better description. If you do mostly city driving and don’t get into the brakes you end up polishing them up to a point where they are more likely to make noise. The same applies to the rotor. It can get nicely polished over time. New pads or turned rotors will have a rougher surface that will act against the other part. There are products on the market that will dampen brake squeal and consist of a tube of goo applied in strips on the back of the bad. They are designed to absorb vibration.
Sometimes you can break the “glaze” by getting on the brakes hard. Take the car out somewhere isolated and give the pads a workout. You’re not trying to lock them up and you don’t do this for an extended period because you’re not trying to heat them up, just scrub off the surface. 2 or 3 good decelerations from 45 mph should do it if that is the problem.
They want to charge an extra $225 to turn the rotors???
Apparently. Unless I misread/misheard the quote. I’ll shop around, though. 15 years of not driving (regained my license less than two years ago) means I’m not especially knowledgeable about what this stuff should cost. I’ve got a friend here who is very knowledgeable, though, so I’ll talk to him and get his advice. He might even be able to do the brakes for me.
Related question: this is also my first car with working air conditioning. Why do my brakes get soft when the AC is running?
I guess it could have some connection to the power brake booster, which uses engine vacuum, which might be affected by a change in idle speed with the A/C on. It strikes me as a bizarre symtpom though - I’ve never heard of it before.