Brake Drag? Any ideas?

[guy123]

I recently did a bit of a brake job on my 96 Legacy L wagon. This involved resurfacing the rotors on the front, and new pads all four wheels, (the rears did not need resurfacing.) I ended up running into a bunch of problems, (most of which were because of buying crappy front pads.) That's all done, got some good high quality pads, everything went back together great, brakes now work very well with NO noise or squealing at all when braking. The only thing is, when the car is rolling with no brakes applied, if I have the windows down I can hear a distinct brushing sound- faint, but apparent. (this is around 5-10 mph) Sounds just like the pads are brushing the rotors a little too much. All disc brakes drag a tiny bit, that I know, just seems like mine might be too much. The sound was not there before the brake job. I was thinking maybe it would go away once the brakes broke in, but it's been over 150 miles and the sound is just as apparent. I re-bled the brakes today, but that had no effect. Will this go away, or is there something I can do to eliminate it? I just want to be sure this isn't rubbing enough to effect pad wear or fuel economy. I'm probably just being paranoid, but oh well. Thanks.

[Olnick]

Did you clean and re-grease the sliders when you had the calipers loose?

 

I was shocked a few months back when I replaced my pads--bottom sliders were bone dry. Made a huge difference in lessened rolling resistance afterward, in fact my mpg even improved a bit!

[gbhrps]

I would agree with a revisit to your slide pins to ensure that they are corrosion free, lubed properly, and are moving freely. At the same time I would be suspect that you may have partially sticking pistons in the calipers, due to infrequent fluid flushes over the years (the manual says every 3 years). The water absorbed from the air will find its way to the bottom of the calipers and rust a ring around the pistons, and then they stick or freeze up. When you pull your calipers next to check the slide pins, have someone push the brake pedal in stages while you watch the piston at each wheel (one wheel at a time of course). They should move out smoothly. After 2 or three pumps, and before they pop out of the caliper bore, force the piston back in with a large C clamp. Do this 2 or three times, and you may free the piston up enough to prevent further sticking. Obviously during this procedure, if you notice that the piston does not move smoothly, but rather in jagged stages, pop it out and clean the piston with 0000 steel wool, and do the same with the caliper bore to remove any rust. If it cleans up well, showing no scoring on the piston or the bore, clean everything well with brake cleaner, relube everything with fresh brake fluid and pop the piston back into the caliper. Reinstall all parts, and then bleed the brakes. But if you have any doubts about a scored piston or caliper bore, replace the entire unit with a remanufactured one. DON'T take a chance trying to stretch a dollar at the expense of an accident. The procedure I've described worked for me on my wife's last Lexus. A brake squeal showed up at slow speeds on one wheel 6 weeks after I had done a complete brake job on the car. I pulled the wheel and discovered the sticking piston. A quick cleanup with 0000 steel wool and so on, resulted in 2 more years of trouble free driving. Good Luck!

[tcspeer]

Also check the backing plate you may have bent it in a little when working on the brakes, and it may be draging aganist the rotor.

I recently did a bit of a brake job on my 96 Legacy L wagon. This involved resurfacing the rotors on the front, and new pads all four wheels, (the rears did not need resurfacing.) I ended up running into a bunch of problems, (most of which were because of buying crappy front pads.) That's all done, got some good high quality pads, everything went back together great, brakes now work very well with NO noise or squealing at all when braking. The only thing is, when the car is rolling with no brakes applied, if I have the windows down I can hear a distinct brushing sound- faint, but apparent. (this is around 5-10 mph) Sounds just like the pads are brushing the rotors a little too much. All disc brakes drag a tiny bit, that I know, just seems like mine might be too much. The sound was not there before the brake job. I was thinking maybe it would go away once the brakes broke in, but it's been over 150 miles and the sound is just as apparent. I re-bled the brakes today, but that had no effect. Will this go away, or is there something I can do to eliminate it? I just want to be sure this isn't rubbing enough to effect pad wear or fuel economy. I'm probably just being paranoid, but oh well. Thanks.

[guy123]

Thanks for the advice. Today I pulled the brakes apart again and discovered the pads were glazed over. I ended up replacing the pads, rotors, and hanger clips (sliders?), and lubed everything all up and made sure everything moved freely. Now everything seems to be good- after i took it out for a few hard stops to seat the pads correctly. I think that might have been some of the problem- not seating the pads properly, although it was time for the rotors too. The hanger clips or whatever they're called also may have been too dry and preventing the pads from moving away from the rotors. Anyway, hopefully this is the end of this ordeal. I'm keeping my fingers crossed.