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Hey all,
Hoping someone might have some ideas.
6 months or so ago my front brakes (non-brembo) started to squeal under light pressure. Never had any issues with noise before. Pads were getting thin and needed replacing.
I've replaced pads before with no issues and so I did so again with some soft pads. No issues until about 500 miles where they started getting noisy at low speed / low pressure.
I couldn't work it out so took it to a garage. They changed the pads to a harder Bendix, planed the rotors. Same issue. Went back, new rotors were put on. Still the same. They couldn't work it out despite happily taking my money.
Its driving me nuts and in the wet they 10x worse. Every traffic light squeals so loud I think the glass windows will break. Any idea what else it could be? Any similar, tinnitus inducing experiences?
You didn't mention the rear brakes. Could the noise be from the rear? Sometimes it is difficult differentiating where a sound originates in an automobile cabin.
Since you've already answered the question about whether or not the rotors were glaze cut (turned), couple possibilities left:
Did the shop....
- Install chamfered pads (or if not pre-chamfered, did they plane a bevel (chamfer) on the fore and aft edges of the pad like this...
This is sort of an extreme cut at the expense of brake pad swept area but you get the idea.
- Were the "anti-squeal shims" installed and if so, were they treated with that goopy "anti-squeal" spray?
Gnarly fingernail. (NOT mine!!) Ew.
These two very basic items contribute to probably 80%+ of squealing issues.
Finally, proper bedding procedures done? WIthout that, might as well run nails across a chalkboard.
- Install chamfered pads (or if not pre-chamfered, did they plane a bevel (chamfer) on the fore and aft edges of the pad like this...
I very much doubt this would have been done nor would the pad have come pre-chamfered. I didnt even know this was a thing! Very interesting.
- Were the "anti-squeal shims" installed and if so, were they treated with that goopy "anti-squeal" spray?
I did this when I put the softer replacement pads on and made sure they did the same with the newer ones which are a lot harder. Worth redoing that possibly?
Bedded in was told they did it but when i went back to them they said it can still take a good 500+ miles to be bedded in properly.
After the amount of mileage ive done on them so far - probably 2000 miles, that wouldn't have sorted out any bedding issues?
Were the caliper guilde pins cleaned and greased?
Same as above really, I did them originally and told them to do this but cant be guaranteed. Maybe i need to look at redoing it all again myself. Just strange I never had any noise issue for the couple years before.
Thanks again for the replies. All good information
As an update, I actually went out and tried to bed them in again (if thats even possible after a few months of use as maybe the garage never did and just lied.)
Left the car overnight for the brakes to cool down and surprisingly in the morning the issue feels almost gone. I only gave it a short drive so need to do another test but whilst it hasn't eliminated the noise altogether, its loads better. Maybe I need to do it a few times to get more transfer on? Do harder pads generally take more to bed in than softer ones? Also being that they are new rotors, perhaps it was as you said MicVelo, nails on a chalkboard.
Shall test again and update.
Most pads these days have a scorched coating on them that aides in bedding the pads. If you don't bed them after install and wait after many miles, they will take much longer to bed.
When you're bedding, once you get the system up to temp make sure to drive for a while with minimal braking (ie freeway/highway) to get the temps back down to ambient before coming to a complete stop.
Coming to a stop while the rotors are hot will insulate the section of the rotor that's between the pads, leading to differential cooling and possible pad deposits.
I got one day out of them after trying to bed them again before the noise has come screaming back. A bit of rain overnight did not help.
At least it was a step in the right direction. I shall head out of the city this weekend and try doing a few sets of 10 reps haha.
What would have happened over the last 24 hours after trying to bed them. Was there a bit of transfer gone across that removed the noise for a period of time but the brake since have wiped it all off back to a non-friction surface or something?
After bedding a set of brakes properly, does the transfer last on the rotors permanently?
Thanks again for the info guys, really appreciate it.
Update.
Spent a good few hours trying to rebed them on the weekend. To no avail unfortunately. Called up the Bendix brake manufacturer and they are sending me some of their product called Ceramasil Brake Parts Lubricant to go on the back of the pad. Not confident this will fix it either as I already put some copper anti-seize on there with little to no change.
One thing I did notice though when I took my brakes apart to apply the anti-seize is that they don't have any shims on the back of the brake pad.
Even though these brakes are made for the Z, if this Ceramasil doesn't do the job I think ill have to try some other brakes out that come with a shim on the back.
Anyone have any recommendations for pads designed for low noise?
07-08-2019, 03:21 PM
New Pads, New Rotors still Squealing.
