Upgrading Rotors And Pads - Opinions Needed

[Reflector]

Well.. The positive response overnight on QFM HPX pads seems to of increased. I assumed gslrallysport would make his way here eventually haha.

So to get to a conclusion:

1. QFM HPX front and rears

OR

2. Another option that someone thinks are better and can justify why

I'm now leaning towards the QFM's though...

[Reflector]

Sorry for the bump, but my set up finally arrived

DBA 4000 series gold crossed drilled front and rears

and

I decided to get EBC red stuff pads as I could get them cheaper from over seas.

Not happy. I've only installed the front pads and rotors (rears are still stock) and honest to god, after 2 days of driving, the pads became UNBEARABLE to live with due to this ear piercing screech. I bedded the pads in correctly and they were installed correctly as I'm in the mechanical trade, but on the second day, I had to take the pads out and linish them because the sound was horrific.

I've searched the forums and internet thoroughly and cannot come to the conclusion on what's wrong.

Has anyone else run into this problem with the same pads or same rotors?

[MrStabby]

Not happy. I've only installed the front pads and rotors (rears are still stock) and honest to god, after 2 days of driving, the pads became UNBEARABLE to live with due to this ear piercing screech. I bedded the pads in correctly and they were installed correctly as I'm in the mechanical trade, but on the second day, I had to take the pads out and linish them because the sound was horrific.

What anti-squeal stuff did you use? I have EBC gold (so a more track oriented pad) and have no squeal.

[GTR-N1]

There are other parameters and variables besides calipers, pads and rotors > squeal.

http://www.sae.org/events/bce/honeywell-liu.pdf

[75coupe]

I thought brake squeal is caused by high frequency vibration.

so it shouldnt matter what pads or discs you use, its about how you install them, hence why all combinations your using squeal, take the pads out clean the backs, roughen up the pad itself clean the caliper and disc area of brake dust, use some goo on the back of the pads let it set and install them again... the goo on the back of the pad I believe is supposed to act as a cushion for any vibration, squealing brakes usually happens under light braking.

this is what I do for all the squealing brakes that I have come across, and it usually works...

please someone correct me if Im wrong... Im fairly sure sydneykid also wrote a thread on squealing brakes and all the reasons and solutions

[Reflector]

I thought brake squeal is caused by high frequency vibration.

so it shouldnt matter what pads or discs you use, its about how you install them, hence why all combinations your using squeal, take the pads out clean the backs, roughen up the pad itself clean the caliper and disc area of brake dust, use some goo on the back of the pads let it set and install them again... the goo on the back of the pad I believe is supposed to act as a cushion for any vibration, squealing brakes usually happens under light braking.

this is what I do for all the squealing brakes that I have come across, and it usually works...

please someone correct me if Im wrong... Im fairly sure sydneykid also wrote a thread on squealing brakes and all the reasons and solutions

Ok, everything you've stated above, had been done. I made it very clear to myself that if I was spending $xxxx on brake system I'd be doing a proper job. I stripped everything down after I blew out all the dust

from wheel->spacers->caliper->rotor

then I blocked the brake hose inlet to the caliper and thoroughly washed the calipers a non oil based solvent that we use at work to clean parts. The faces of the pistons were lightly sanded to remove existing anti-squeal goo. They were then blown off using compressed air till completely dry.

After I finished painting them etc... I fitted the new rotors, fitted the new EBC redstuff pads (which I installed the included shim on the back) then put the parts an necessary. (did a minor bleed as there was no air in the system and I'd just recently flushed it)

I didn't put brake good on at first because I assumed the shims would do their job.

After reading that the red stuff pads have a bedded in compound, I assumed it might be normal for the to squeal a bit until that was gone. But even after bedding the pads in, not even a day later, ear piercing squeal set in.

SO THEN I took the pads out, linished them (to get rid of the shine) and placed them back in with some brake goo (to answer Mrstabby, I think it was the orange CRC brake anti-squeal).

After 2 days now, the squeals very slowly and discreetly coming back.

I am at a loss wondering whether to sell these pads and get more... but I just can't justify spending $xxxx on new brakes and it not fixing the problem that resulted in the change.

[75coupe]

yeah ok, it sounds like youve done your best to install them right...

Ive tried a fair few pads over the years and from that experience and from reading threads online there doesn't seem to be a consistent brand that will squeal, there has to be another factor, otherwise you can imagine how many cars would be experiencing the same problem...

next move, brake specialist and give them the mission to rid your setup of the squeal, if they succeed ask them for the secret, if they dont, surely they will have a good explanation other than change pads or rotors...

I'd be interested to see what a decent brake workshop would say...

[75coupe]

have you tried giving the edge of the pad a chamfer, Ive always just given my pads a rub some flat concrete and chamfered the edges sightly... Ive never had a squeal I couldnt get rid of, it may take me a couple of times but eventually something I do on install or re-install does the trick... Im no expert though, hence why Im a bit hit and miss...

[Reflector]

haha well, the red stuff pads are chamfered stock and they also have a split down the middle of the pad to release dust etc... when I refer to 'linishing' the pads, it's just using a belt driven sander to grind the pads, much the same as doing a figure 8 on a piece of sand paper.

I'd really like to get to the bottom of this problem. Apparently it started when the 2nd owner of the car installed a set of slotted discs on the front, and since then there's been a squeal - regardless of the pads used, even on brand new rotors.

Is there a possibility the pistons in the calipers could be creating this squeal? I wouldn't think it possible... but then again I wouldn't think that a brand new set of rotors and pads would create horrificc screeching 2 days in

I noticed my rotors are extremely shiny, I did prep them by running over them with brake cleaner to remove the anti rust coating (as described in the packaging) but I find it odd for the rotors to still be so shiny, because I know that can cause noise...

[MrStabby]

I like EBC pads so IMO you should persist with working on the installation rather than trying new pads. Take the mindset that the installation is not right, and work from that perspective.

The factory shims require a special grease to be used with them, they're not made to be used clean by themselves, so its not surprising they didnt work. It sounds like you have the backing shims, but what about the corner ones?

FWIW when i had factory calipers i used the shims with the red goo (not the grease) and got it silent. There was still a little grease between the two plates tho, so it was piston -> goo -> first plate -> grease -> second plate -> pad (or maybe there was goo between the second plate and the pad as well). I did a bit of trial and error to get it right, i should have just read the workshop manual....

There are a bunch of complicated and interconnected reasons you can get squeal - its not a simple thing.