Squealing Brakes - Solution?

[AussieN14]

I have an N15 pulsar that has a R32 GTR front brake upgrade fitted (non-vspec sumitumo 4-piston calipers).

Not using adapter plates, using an N16 knuckle which the caliper bolts straight onto.

The brakes scream like a banshee sometimes (F**KING LOUD!!), when they're cold they do it, when they're hot they do it... sometimes they shut up and then it comes back again, usually only happens on light braking (like normal driving)

Discs are DBA4000 slotted items, which have done quite a bit of track work, used ferodo ds3000 pads on the track

I've tried the 3000's on the street, tried lucas pads, bendix ultimates, and am now using standard nissan pads (200sx factory pads) and they still scream like a bitch under light braking. I've put in the nissan factory shims behind the pads which has that orange goo as well, hasn't helped. Still has the caliper pins and the retaining springy bit that pushes down on the pads. Have even rebuilt the calipers with a genuine nissan kit, didn't help.

I'm thinking that maybe cause the discs have copped a lot of abuse on the track the heat cycles may have affected them somehow?

Any thoughts?

[E-Z]

spray some WD40 on them

[rowdytoot]

just leave the middle pedal alone..

[willsy01]

spray some WD40 on them

This!

I've got DBA 4000s and Ultimates on the Sube and it does the same thing under light braking. I've not bothered trying to remedy it though due to out and out laziness......I just turn the radio up or shut the windows.

[AussieN14]

just leave the middle pedal alone..

i do this already, brake late and hard to avoid the noise, but since it's essentially a stock brake setup (albeit out of a different car) it really shouldn't be doing it i would have thought.

Unless it's just the 4000's causing it like willsy said - i know of other pulsars with the same setup, same discs and no noise, can't see how mine is different.

[stockymcstock]

remove discs, spray the fuck out of them with brake cleaner (or get them machined) to remove the light film of pad material that's melted to the outer surface. simultaneously make sure you give the pads a light going over with 400 grit, or change them to a clean (non-contaminated) set. Could be an interaction of the material on the disc (not the metal, the residual brake pad dust/film) and the pad which is also contaminated with the same gunk.

[AussieN14]

it's worth a try, should i be doing anything to the discs like sandpaper etc.? or just wetting/soaking them with the brake cleaner and a wipe down?

I've tried roughing up the pads on the concrete, which works for a few k's then comes back, but if the problem's in the disc i'll give it a go.

cheers.

[stockymcstock]

yeah you need to do both simultaneously. obviously you've got an unusual problem because others are using the same combo of stuff without issues, but nobody has used your particular set of pads in the past then changed to what you're on now. It will be some weird interaction between the particular pad residues that is causing the squeal if you've changed everything else.

Easy enough to do too - whip the pads out, spray the fuck out of the the rotor with brake cleaner and wipe with clean rag, then sandpaper pads and whack em back in. they will need to bed in again obviously.

[AussieN14]

ok sounds good, i'll give it a go, thanks for your help.

[BundyBeej]

Had the same thing with DBA Street Slotted and Bendix Ultimate pads...light breaking would make squeeling. Switched to QFM HPX pads and that seems to have made a huge difference. Every now and then there is a very slight squeel on light braking, but nothing compared to with the Ultimates.

[MRMOPARMAN]

also chamfer the edges of the pads slightly, along with what stocky said. if that doesnt fix it, it will be your pads. i know lucas (trw) pads squeal (they do on my GTR). havent used bendix in years so im not sure on them

[dynoryder]

break squeal is a massive subject among brake companys

that being said champher the leading edges of the pads on two angles this pretty much gets rid of it

some pad makers make the pads to tight to stop it but then they give the disc dtv lol

if you could bring your car to me i could fix it in half a day easy

[dynoryder]

remove discs, spray the fuck out of them with brake cleaner (or get them machined) to remove the light film of pad material that's melted to the outer surface. simultaneously make sure you give the pads a light going over with 400 grit, or change them to a clean (non-contaminated) set. Could be an interaction of the material on the disc (not the metal, the residual brake pad dust/film) and the pad which is also contaminated with the same gunk.

no dont machine unless the discs have dvt

also if sanding pads drop a sheet of 400 on the flattest bech you have and lighty rub them to keep the face even

machineing is good for dvt or glazing but if it were my car i would replace not macine i use dba4000's and they really need to be ground not machined as the slots reek havick on the brake lathe

[MRMOPARMAN]

if your breaking tips on the brake lathe from slots/crossdrilling, your doing it wrong. you just have to take it nice and gently. takes longer but saves money buying tips.

[dynoryder]

if your breaking tips on the brake lathe from slots/crossdrilling, your doing it wrong. you just have to take it nice and gently. takes longer but saves money buying tips.

no the slots makes the lathe squeel it's tits off which is not ideal for a smooth finish

pbr have lathes that can do it but they are worth alot of money and yes i have been to pbr's factory

[bpm]

Wtf I machine slotted and drilled rotors all the time with no dramas. And I will always give em a light skim if they are sqealing, fixes it every time

[MRMOPARMAN]

^ this. you can also get dampeners that help stop the squealing a little too.

[AussieN14]

i pulled the brakes apart, cleaned all surfaces with brake cleaner (several times) and roughed up the pads with sandpaper,

worked well to begin with but once the pads had bedded in again the squealing returned, albeit not as bad as before but still pretty bad sometimes.

I'm going to try giving the discs a light skim if i get a chance, see if that fixes it.

[da9jeff]

T'were me Id give the discs a light scuff with some emery, dont go crazy with it and try to work in circles and obviously work the whole surface evenly. You just want to break the glaze on the disc to let the pad bed in properly.

FWIW my s14 with 32gtr fronts and a1rm pads never squealed, but a mates R34gtt (same brakes) with some racey metal pads squealed like a pig until I made him buy some A1RMs.

[Cracka]

T'were me Id give the discs a light scuff with some emery, dont go crazy with it and try to work in circles and obviously work the whole surface evenly. You just want to break the glaze on the disc to let the pad bed in properly.

FWIW my s14 with 32gtr fronts and a1rm pads never squealed, but a mates R34gtt (same brakes) with some racey metal pads squealed like a pig until I made him buy some A1RMs.

My A1RM's are squeaky motherfuckers

[gslrallysport]

I would definitely get the rotors machined and start again. Brake cleaner will not remove brake material that has been bedded in to the rotor. If you have gone from one pad compound to a completely different pad compound say EBC to Bendix, and have not had the rotor replaced or at least machined between the transition of pad materials then squealing is just one of many problems you could be faced with.

[da9jeff]

mine never were but i did have the shims fitted, maybe they actually work?

[AussieN14]

I would definitely get the rotors machined and start again. Brake cleaner will not remove brake material that has been bedded in to the rotor. If you have gone from one pad compound to a completely different pad compound say EBC to Bendix, and have not had the rotor replaced or at least machined between the transition of pad materials then squealing is just one of many problems you could be faced with.

ok cool, yeh will get them machined and go from there, cheers.

[XAC15T]

cbf reading... shims?

[AussieN14]

cbf reading... shims?

lol, first post mate - already have all that shiz.

[AussieN14]

so.... new (quite soft) pads, rebuilt the calipers (again) as they needed it - were quite jammed up apparently, new shims etc...

still squealled

machined the discs which are almost at minimum thickness now and the noise stopped - for a while.

Once they were bedded in (proper bedding in procedure) and then after a bit of normal traffic driving the noise started to come back.

if i take it for a thrash with lots of hard braking, the noise goes away for a while, even the next day it's not there until i drive in normal traffic for a bit.

I think it's glazing up in normal traffic, possibly due to being a bit overbraked for the car, normal driving you can breathe on the pedal and the car will stop just fine, i think constant very light braking is causing the glazing and the noise, and some hard driving gets rid of it for a bit.

Waiting for new discs to see if they help as they need replacing anyway, but it's a custom order from DBA with a 8-12 week leadtime (if they ever do them at all). Or i'm just gonna drive harder from now on :P

[dynoryder]

I run 4000's and ultimate's on my commodore they squealed for the first 2-3000km but after awhile the squealing subsided.

If you are using a complete oem setup bedded in properly then the brake's should never squeal but when using aftermarket compounds and rotors you can get squeal. I would think if you just buy a new set of rotors and pads and don't change pads just let the squeal die down you should be fine IMO.

What causes the squeal on slotted rotors is the energizing face of the pads tapping the slots but as I said mine squealed then it just went away by itself one day I have no fucken Idea why.

[Stix Zadinia]

i assume it doesn't have the anti-squeel on the back of the pad?

[dynoryder]

i assume it doesn't have the anti-squeel on the back of the pad?

I would not put that shit any were near my brakes if they are alloy.

[simpletool]

I read the thread and thought copper grease from the very beginning, reading each post only confirmed my thoughts.

I had problems with R33 Sumitomo calipers, DB4000 (non-slotted) and RB74 pads. Exactly the same symptoms - squeel on moderate braking, disappears for a day or two if you get them hot, then squeel again. I tried everything and the thing that worked was copper grease. Apply a light film to both shims, inside and out. It will last ~20,000km or so.

I can't see what damager it will do to alloy calipers, it won't even touch the calipers unless you are using way too much. The most detriment it would do would be to the rubber seals.

I have done 80,000km since then, regreased a couple of times and rebuilt the calipers (no evidence of damage to the alloy or steel pots). I now run Ultimates, soon to be Comp 9 and HPX. I will be putting a thin film of cooper grease on the shims for both pad types.