Brake squeals - not the pad

"GreenN_Gold" (GreenN_Gold)
12/23/2016 at 17:59 • Filed to: None

My left rear brake squeals when brake pressure is applied, but it’s not the pad. The pads have been replaced. The squeal existed both before and after the pads were replaced. Possible causes?

I can affect the squeal with the amount of pressure I apply to the brakes. I’m guessing there’s something on the surface of the rotor? The squeal actually seems a bit louder now that there are new pads.

DISCUSSION (23)

crowmolly > GreenN_Gold
12/23/2016 at 18:06

Did you resurface or replace the rotors or just pad slap?

Twingo Tamer - About to descend into project car hell. > GreenN_Gold
12/23/2016 at 18:11

Some cars just do it from new, there may be nothing wrong with it.

Die-Trying > GreenN_Gold
12/23/2016 at 18:12

brake dust?.......

If only EssExTee could be so grossly incandescent > GreenN_Gold
12/23/2016 at 18:14

I bet you have a piglet lodged in your rotor. The squealing is louder now because the new pads are squeezing with more force

GreenN_Gold > crowmolly
12/23/2016 at 18:16

Just pads

GreenN_Gold > Twingo Tamer - About to descend into project car hell.
12/23/2016 at 18:17

The car is not new, the squeal is new.

GreenN_Gold > Die-Trying
12/23/2016 at 18:18

I doubt it, the car has been washed, unless there’s brake dust on the back of the rotor that isn’t getting removed.

GeorgeyBoy > GreenN_Gold
12/23/2016 at 18:19

What kind of pads?

crowmolly > GreenN_Gold
12/23/2016 at 18:24

I am not a brake compound engineer, but my understanding of squeal is that it can be from uneven pad material transfer to the rotor surface. Part of the reason you R&R the rotor is that it gives you a clean surface to burnish the new pad on to. *Sometimes* if you keep the compound the same you are OK, but replacing just the pads on a used rotor with no resurfacing is a gamble.

Twingo Tamer - About to descend into project car hell. > GreenN_Gold
12/23/2016 at 18:24

Some pads need the edges filing before fitment, it’s possible that wasn’t done?

GreenN_Gold > If only EssExTee could be so grossly incandescent
12/23/2016 at 18:25

If I squeeze hard enough do you think I can kill the sucker so it will shut up already?

pip bip - choose Corrour > GreenN_Gold
12/23/2016 at 18:25

maybe it needs new shims , generally you only get them with genuine brake pads.

GreenN_Gold > GeorgeyBoy
12/23/2016 at 18:26

I don’t recall off hand, but I doubt it’s the pads since the squeal was present with both the old and new pad, and the other 3 same-brand pads are all silent.

GreenN_Gold > crowmolly
12/23/2016 at 18:28

I knew it was a gamble, but the brakes pads were replaced in my buddy’s garage. We did not have a lathe with which to surface the rotor. I was thinking the pad had just worn down to the squeal bar, but nope. There was still pad life left, and the squeal remains.

Die-Trying > GreenN_Gold
12/23/2016 at 18:29

the grooves from natural wear can trap dust in them, and cause a squeal. also depending on what they are made from, some pads make more noise than others.

GreenN_Gold > Twingo Tamer - About to descend into project car hell.
12/23/2016 at 18:30

It wasn’t done (or needed I think), but the squeal was present before the new pad, and the other 3 new pads are silent.

crowmolly > GreenN_Gold
12/23/2016 at 18:30

Did you at least put the anti-squeal goop on them?

GreenN_Gold > crowmolly
12/23/2016 at 18:31

Yes, affirmative.

Phatboyphil > GreenN_Gold
12/23/2016 at 18:34

You can take it to O’reilly. They do two for $30 I think

Twingo Tamer - About to descend into project car hell. > GreenN_Gold
12/23/2016 at 18:36

I would just do the usual, clean slide pins and give the backing some copper grease as others have probably said.

My twingo started squealing a while back and id completely forgotten about it until i was reading this post. The noise mustve randomly disappeared. I did clean and grease everything, but that didnt immediately stop it.

GreenN_Gold > Phatboyphil
12/23/2016 at 18:39

Do you mean O-O-O-O’Reilly?

This may be what needs to happen. I was hoping new pads would fix it (which I needed regardless of the squeal).

GreenN_Gold > Twingo Tamer - About to descend into project car hell.
12/23/2016 at 18:41

Thanks!

I’m holding out faint hope that it will just disappear.

Alternatively, I can just stop by rear ending people or turn everything into a panic stop, because it seems to disappear under very light and very heavy brake application.

If only EssExTee could be so grossly incandescent > GreenN_Gold
12/23/2016 at 20:41

Try doing a couple panic stops from 40mph