Question for those who know brake systems...

[JT95]

My front brakes have started making a grinding noise as the car finishes rolling to a stop. It does this only occasionally. Sounds like if your brake pads were gone, only these were replaced less than a year ago, and it only does it from time to time.

 

Any ideas what this issue could be? I had a tire store do a quick brake inspection and the guy said he didn't see anything, but I honestly think all he did was look at pad wear. It'll be at least two weeks before I will be able to take the time to tear into it myself, and even then I am not a brake man, but I am good at following someone else's lead...

[Fairtax4me]

I know several people who have had this type of problem with brakes. It generally tends to start happening about 6 months to a year after pad replacement. I've never been able to definitively pint this problem down, but I believe it has to do with the way the rotors wear.

 

The pad doesn't usually cover the entire machined surface of the rotor, there will usually be about 1/8th inch of room on either side of the pad where the rotor doesn't wear at all. The area under the pad wears down, leaving a ridge on either side of it. This ridge, since it never gets cleaned off by the pad, also rusts badly, and eventually starts to wear the inner and outer edges (in relation to the hub) of the pads. This traps heat in the pads, and makes them "chatter" as the car comes to a stop. It usually gets worse as the brakes get hot. It also seems to be worse if you use cheap pads.

 

When you look at the rotors, if there is a ridge around the outer edge, take them to a machine shop and have them turned. Or just replace them if you want, but generally it's 10 - 15 bucks each to have a rotor turned and new rotors cost $30 or more a piece.

[idosubaru]

it's a good idea to pull the wheels and check both pads on each side too. i've seen numerous times where one pad was done in less than a year. cheap pads, a dirty caliper slide, etc will cause premature pad wear.

[JT95]

Thanks for the feedback. I will pull my rotors in a couple weeks and have them turned. Probably should have had that done already as standard maintenance. I replaced the pads myself. Been doing pads on my Subarus for several years now, so I don't think it was a screw-up on my part with how things were reassembled. Plus that was months ago.

 

Pads were mid-grade. Not the cheapest, but not top shelf either. They did come with a lifetime warranty, which I don't really understand on parts that are supposed to wear out, but that's neither here nor there.

[idosubaru]

Turning the rotors is a good idea.

 

I haven't seen it on Subaru's but I've seen other vehicles blow through brake pads in under a year.

 

"Lifetime Warranty" doesn't mean much in terms of quality. Often it means low grade in this biz.

 

Another way a pad wears quickly is if the clips in the calipers are caked with blackness or have rust. This causes the pad to stick and ride the rotor, saw a 96 Legacy last week with 9 month old rear pads, one was done due to hanging on a rust spot on the caliper clip.

[JT95]

Thanks, Gary.

 

I have some serious vacation time coming up at the end of the month, so I will dig into the whole assembly on both sides and do a thorough check. My Roo is needing some TLC in other areas as well, so that's how I plan on spending the first two weeks of June.

 

 

...and then I gotta figure out how to fab a bracket to mount the supercharger I just picked up.

[idosubaru]

Awesome, good luck!

How's the rotor turning market? Last place I lived machine shops didn't even like turning rotors. Now where I live lots of places do it and it's cheap. I'd imagine your area is easy to find folks to do that, might take a few phone calls if you haven't had it done before.