noisy front disc brake after pad replacement

[gerrymcm]

I've recently replaced the pads on my hydraulic disc brakes and bled them at the same time. I replaced the Shimano standard ones with a cheaper make, discobrakes I think but I stuck with the same type, i.e metal sintered. Now when the front pads are wet I get the most annoying squeal/shudder/reasonance from the front fork. As it dries it decreases and goes away but id like to eliminate it completely and go back to nice quiet braking.

I took the brakes completely off and cleaned them as they had many years of crud and inspected the mounts and brake adapters etc so it's possible that something has not gone back perfectly but I've had the brakes off a few times over the years without problem.

Please could people offer some pointers.

Thanks

Gerry

[DevonDamo]

Changing brake pads alone can cause squealing in the wet. I get my pads from Superstar Components. Their sintered metal pads are always silent, and are excellent value for money. However, last time I ordered some, they were out of stock, so upgraded me to their kevlar ones for free. These squeal when wet.

It could be that you have other problems following the rebuild. However, I'd first check with some known 'non-squeal' pads. (Nobody will be able to diagnose a fiddly little problem with your brake reassembly through what you write on here.)

[gerrymcm]

Sounds sensible. I kept the old pads and the back pair were not that worn so maybe I'll go back to them for a test.
I reckon I'll strip and set it all up again just in case and maybe splash on the Shimano originals.

Thanks
Gerry

[Milfred Cubicle]

I don't want to insult your intelligence, but did you 'glaze' the pads before use?

[gerrymcm]

Milfred
I'm not insulted and thanks for chipping in.

When you say "glaze" them before use, does that mean give them a rub with sandpaper or abrasive surface?
If yes then I didn't do this as I assumed that being new they wouldn't need it. I thought this happened after you "dragged" your brakes.

What I've read from a few places on the web is that once fitted new pads should be vigorously applied multiple times to "bed them in" i.e. make the pads mate to the circular groves on the rotor.

I thin I've got a few things to go on but any more suggestions would be welcome.

Thanks
Gerry

[andrewjoseph]

I use superstar and disco pads on my mtb and road bike, trying the Kevlar pads after using sintered for years.

I find them quieter but occasionally do squeal a bit.

If it's really bad, put some gritty mud on rotor and do some hard stops. Clean and check for noise.

I use meths to clean rotors and pads.

[Brucey]

on most disc systems it is a good idea to put a little anti-seize on the back of the pads. This can help quell the vibrations that cause squealing.

On car and motorcycle brakes 'anti-squeal shims' between the pistons and the pads are commonplace but I've not seen similar items on bicycle brakes.

cheers