intense_27

Since I don't have enough posts and can't post anywhere else, I will ask my technical question here:

The issue:
Under soft braking, I'm experiencing a squeaking noise coming from the left rear of the car (coincidentally the parking brake corner). Sounds like a squeaky spring. It happens every revolution, and as mentioned, only with soft braking. If I hammer on it, there is no oscillation, and no noise.

What I've done:
I pulled the left rear wheel off to inspect the brake components. Lots of life left in the pads, rotor shows no scoring or uneven wear. Parking brake mechanism is all in tacked and operates properly while stationary.

I also attempted to adjust the parking brake to see what that would do. Loosening it wouldn't do anything. Tightening it made it a bit better for a short period of time, and then got worse again.

Thoughts?

04Green

iTrader: (1)

Pull the pads, lightly sand the surface with 100 grit paper to clean them, re-install.

Also, what type of pad?

intense_27

I'll give that a shot. You don't think it's something related to the parking brake?
Not sure...I haven't owned the car long enough to have to change the pads. When I take them out, I'll see if I can figure out what they are.

04Green

iTrader: (1)

parking brake will not squeak, pads squeak.

now, parking brake can drag, heat up pads, glaze them, then make the squeak.

Also, get some grease, make sure all the pins are lubricated, as well as where the pads hit the metal clips that help hold them in. Put some on the back of the pads as well. Those are all squeak generation areas.

also, miles, model, type of pad, things like that would help.

Do not get grease on the rotor or pad face. That is not good.

intense_27

05 6MT, 125,000 km, unknown pads

Thanks for the advice, worked like a charm

niteshade247

I'm thinking the same here sounds like you or the owner befor had to stop fast and glazed the pads might be a good thing to sand both sides to ensure you get equal braking on both sides.

intense_27

Just to bring this back for a moment....the noise came back, so I serviced them again..both sides this time. After a couple weeks it was back for a third time. Same corner each time. I have done brakes before so I am confident with what I am doing. No significantly hard braking. Also, it's more of a squishy squeak...not a glazed or rivet-rotor squeak if that makes a difference

Is there a chance this could be a case of crap pads and/or rotors?

patriotjj

The only input i can say about squeaks would be the pads are cheap. If they are the cheapest set from an autozone, O'Reiley, etc, they will squeak. If your car or steering wheel isnt vibrating on braking then i dont think its the rotors. Hmm.

Mysterion

They might also be expensive. Sounds almost like what I ran into few years back on a Dakota Pickup with ceramic pads. The painful part is that to eliminate the squeak we ended up having to replace the pads and turn the rotors. Personally, I now use exclusively organic pads. Even though they don't last as long, at least they remain quiet unless glazed.

Easiest way to tell if they are ceramic is to use 60 grit sandpaper and scuff the heck out of them and do the same with the rotors. Just be sure to keep the scuffing as even as possible across both the pads and both sides of the rotor. If they are organic or semi-organic, they should scuff up nicely but if they are ceramic, they will seem to be nearly unaffected by the scuffing.

patriotjj

Dang, smart and nice little troubleshoot info, I never knew that.

Mysterion

Been there, done that. When it first happened, it drove us crazy trying to figure it out since the truck's owner paid thru the butt for the pads figuring more was better. Nuh-uh.

intense_27

I understand requiring to replace the pads, but why re-surface the rotors? Would a proper bedding of the pads get rid of the previous pad deposits on the rotors?

Also, I did use a courser grit (80 I believe) paper the second time around and noticed that there was quite a bit of material scuffed off on the pads. I'm getting to the point that I'm just going to replace the pads, but hoping that I don't have to touch the rotors.

Another side question...when you found the issue on the truck, was it by any chance on the e-brake wheel?

niteshade247

Sounds like the e brake is riding the brake seeing that it's only happening on that side or you caliper is not returning to the correct potion and reglazing the pad. Could be that the rotor is glazed as well.

intense_27

That's what I thought originally, so after I did it the first time, I backed the e-brake way off, and the noise still came back. I inspected the e-brake and I am very confident that it's working properly

I also gave the rotors a good sanding. Not the same as re-surfacing obviously, but should have helped

niteshade247

Could just be a bad set of pads. If they are carbon metallic pads they tend to make a lot of noise or as I mentioned a sticking caliper.

Mysterion

Brake Service 101:

When the brake linings contact the metal surface, braking is caused by the friction created by the contact. Friction creates heat and that heat can harden the contact surface . The hardening of the contact surface creates a glazed condition which, when contacted further by the friction material, allows the material to slip more, reducing braking power. The slippage also causes a squeaking or squealing sound as the friction material, which is also hardened by the friction, literally slides along the metal surface rather than gripping and attempting to stop all movement between the two materials. The harder and more glazed the metal and friction material, the less stopping power your brakes will have. Eventually, the slippage will become so bad that you will need to carry a large anchor to throw out when you need to stop as the glazed and hardened brake pads and rotors won't be able to grip enough to do it. Replacing pads only is like painting a car without sanding first. It's a shoddy job but, unlike a poor paint job, a half-assed brake job could one day hand you your ***.

540RX8

The fact that it's coming from the same corner even after you've removed the pads a time or two now I'd go with either a slightly warped rotor (easy fix) or possibly a caliper that's slightly sticky (medium hard fix). Easiest step is to spend ~$20 to have someone turn the rotor. As long as it's got enough thickness to allow a resurface. Remember to scuff the pads again after resurfacing the rotor. If the squeak returns I'd bet you have a sticky caliper that drags the pad causing it to glaze over and vibrate at light pedal pressure. Good luck!