bluebarchetta
bluebarchetta Reader
12/1/15 9:28 a.m.

2001 Saturn SL2. Under braking, I hear a noise like honing a piece of wood in a lathe and feel gentle pulsation in the pedal. So I replaced the pads and rotors and the noise went away, then it gradually came back over the course of the next 10K miles. Scoring is appearing on the outside of the right (passenger side) rotor. The inner surface of that rotor appears fine, as do both sides of the left rotor. So I replaced the right-side caliper bracket and slider pins, and lubed the pins well with Sil-Glide. (I also cleaned and lubed the driver-side pins, but did not replace them or the driver-side caliper bracket.) Again the noise went away, then came back again after another 10K miles.

I'm thinking the next step is to replace both calipers (which come with new brackets and pins) and do rotors and pads again. Do you think that will fix it? What else could it possibly be? No odd tracking/handling issues, so I doubt anything is bent suspension-wise.

I could afford to trade this car, but we bought it new, it's been paid for since 2006, it runs great, and it frees up funds for things like beach vacations and frivolous Miata part purchases.

Thanks!

Robbie
Robbie SuperDork
12/1/15 9:31 a.m.

Hows the wheel bearing on that side? I'd guess calipers would fix it too, but just a thought.

oldtin
oldtin UberDork
12/1/15 10:28 a.m.

the description sounds like a sticking piston. either rebuilding or replacing should fix it.

GameboyRMH
GameboyRMH MegaDork
12/1/15 11:01 a.m.

Sounds more like a slider or wheel bearing problem, to cause damage to only one side of the disc. I'd also check for any foreign object in the caliper or bracket that could be scoring the disc - maybe a pebble is stuck somewhere, or a badly positioned / wrong spec brake pad clip?

flatlander937
flatlander937 Reader
12/1/15 11:35 a.m.

Nearly every time I've heard what you describe its been pads becoming unbonded from the pad backing plate.

Have you checked the pads?

I agree I'd be looking at calipers if the pads check out though.

I have had a few brake hoses fail internally and hold the pads against the rotor, but generally causes some weird drivability issues too.

pjbgravely
pjbgravely Reader
12/1/15 9:05 p.m.

I had the exact same problem with a 94. I never figured it out before I finally junked it. I ended up deciding that it was actually warping the rotors somehow despite hardly using the brakes. The front end looked like it was made from tinker toys so it probably was a slight imbalance making the whole front end vibrate.

bluebarchetta
bluebarchetta Reader
12/2/15 8:08 a.m.

Passenger-side wheel bearing is a good guess, but I had it replaced this past summer (I don't have a press). Not the pads, either - this is the second set of pads that has produced the same symptoms after ~10K miles. I didn't see any foreign object, but I never considered that it might be related to the brake pad clip.

I think I'll arbitrarily decide that oldtin is right and it's a sticking piston. Two rebuilt calipers and another set of pads and rotors are still less than a single car payment, right? And if the noise comes back in 10K miles, I'll be a year down the road and still money ahead.

Thanks, everybody.

belteshazzar
belteshazzar PowerDork
12/2/15 12:57 p.m.

ive had that problem on a saturn before. in my case it was the friction material coming unbonded from the backing plate.

Our Preferred Partners
1RBdOBnMflexVnALg2o9bmzAbZfqyzXeKOJXMxSzQeCE4sUJKG2PghZtM8VjyKFJ