brake pad completely worn down

[Chris Briggs]

Last week my wife told me her brakes were making noise when she used them, but that there was also noise after using them. It seemed to come from the right rear wheel. My old car (’05 Accord) showed the same symptoms last year (though front left wheel). In that case, the noise was from one pad being completely worn away and I found a stuck slider that explained why that happened, and why there was noise after releasing the brakes (because they clearly weren’t releasing).

So I ordered pads, rotors and hardware for my wife’s car (’10 Subaru Outback, 68,700 mi). Her brakes were last done (pads + rotors) on all four wheels about two years (and 20k miles) ago by a mechanic. (It was after that I decided to start doing brakes myself — this is my third time.) This was the first brake problem on this car since then. Tonight I pulled off her rear wheels and, not surprisingly, found the outer pad on the right to be completely worn down. I replaced the pads and rotor on that side. The sliders seemed ok, but I lubed them (with silicone) anyway and replaced the boots. I had no trouble compressing the piston (followed Eric’s video — pinched the line, opened the bleeder, ran a tube from the bleeder into a bottle containing some brake fluid, etc.). Also no trouble bleeding the system after that.

Since the sliders and piston seemed to move ok, do you have any ideas why one pad got completely worn down while the other still had about 50% left?

On the left rear, both pads have about 50% left and the sliders seems fine. I left those pads + rotor on for the moment because it got late and dark. I’m just wondering, how necessary is it that I replace the left rear pads + rotor in the near future? Is there actually a problem if one side has pads at 100% and the other side has pads at 50%? I can replace them this weekend, but part of me is wondering if I should save the other pads and rotor I bought in case the right side wears down prematurely again.

Thanks for any info.

Topic

[Richard Kirshy]

Just a thought here.
Did you happen to check to see if the pads are perhaps binding up when installed?
The caliper may well be functioning without issue, but if the pad(s) are hanging up that may be your issue.

[Chris Briggs]

That appears to have been the case. I just took another look at the old hardware and it had some build-up that would have prevented the pads from sliding easily. Good video. Thanks.

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