Brake squeal - NOW faulty pads perhaps... anyone seen this before?

[1JZ-Rolla]

Did a search but found nothing conclusive...

I've recently fitted Queensland Friction Material's A1RM compound track pads to my AE71 Corolla, which runs a Hoppers Stoppers 290mm brake kit (twin spot sliding caliper).

After bedding in the pads, they have a horrid squeal when driving with NO brake applied, like a constant high pitched oscillating noise, both sides. The pads make no noise at all once light brake pressure is applied, regardless of hot or cold.

I checked the obvious things: caliper anti-rattle spring plates fitted, wheel bearings adjusted, mounting surfaces between caliper & pad backing plate clean, but all to no avail.

Any pointers on how to kill this annoyance? I know some people use a high temp lubricant on the back of the pads, but to be honest i'm not really keen on putting anything liquid near the discs cause they must get damn hot at the track.

Cheers
Phil

[fixeruperer]

you can get anti squeal spray that you spray on the back of the pad (it drys) and that stops squeals sometimes.
if they're comp pads there going to squeal and theres nothing you can do about it but if there squealing with no pedal pressure theres something else touching, to totally eliminate the pads buy some cheap cheap pads and wack them in and see if the noise stops and go from there.

sometimes chamfering the outside edge of the pad can stop squeals too.

["Z" UTE]

Yeah mate the red anti squeal compound on the back and sides of the pad works well. Dries to a rubbery consistency, and absorbs small vibrations.

cheers Chuck.

[1JZ-Rolla]

Does this product have a brand & particular supplier?

["Z" UTE]

CRC "Disk Brake Quiet", borrow mine if you like.

Probably purchased it at Repco, or Auto Pro down in Tuggers.

cheers Chuck.

[1JZ-Rolla]

I knew you'd have the detail Chuck

If you're ok with me trying it, i'd appreciate borrowing yours thanks. If its a winner, then a can of the stuff will find a permanent home on the shelf in the garage

["Z" UTE]

No worries Phil, it just too a walk out to the shelf in the COLD garage. Drop by anytime,

cheers Chuck.

[fixeruperer]

i use wurths anti squeal, not shaw where you get it from becuase we order it from wurths and they drop it off.

["Z" UTE]

Yeah my lad uses the same Wurth stuff in a spray can, again direct delivery to the workshop.

cheers Chuck.

[1JZ-Rolla]

I may have found something that is contributing to the squeal.... and even if its not the cause, I think I should be concerned in any case!




As you can see above, the friction material is not bonded to the backing plate for the entire surface, I can see a gap between the two extending from the leading & trailing edges for about 40mm, enough that I can slip a sheet of paper inbetween.....

Manufacturing fault perhaps? Anybody seen this before?

Cheers
Phil

[YLD-16L]

Just had a look at 4 different brands of used pads and none are like that at all.

Looks bad and I suspect potential for the un-bonded part to break off

[1JZ-Rolla]

That's what i'm afraid of, there are already fractures in the friction surface, which is not uncommon with heat-cycling I guess, but combined with not being bonded could mean a large chunk coming away altogether.

Guess I better visit the place I bought them from on Monday.

[RA35GT]

Definately dodgy manufacturing there!

[thechuckster]

let QFM know directly - a few rally guys up here use them without issue (and gravel rallying is not easy on bakes) so interesting to hear that the backing plate bonding has failed.

[DrNick]

Up until recently that anti-squeal compound (I use the dynagrip one) has fixed everything. However one of my cars developed this noise under light braking which was very hard to get rid of. I removed the pads, cleaned, applied anti squeal, removed rotors and deglazed them and also deglazed the pads... Reassemble and its still there. After 2 or 3 attempts i swapped the pads over between the left and right sides and it fixed the noise.
Still have no idea why it started (they werent new pads) but i just thought the info might be useful to somebody.

In the case of the OP, my money would be on that friction material and I wouldnt put it back on like that. Try and get the supplier to warranty the pads.