Squeaky sintered brake pads

Muckers

Hi all. My mtb has very noisy front and rear sintered disc brake pads. They're ok when applying light pressure at the lever, but when braking harder to stop they get very noisy. And when I say noisy I mean noisy. They would wake the dead. I thought maybe it was the pads, so today I fitted new pads to the front but it made no difference. Surely it can't be the rotors. Any advice here would be very welcome.

smacl

Given the noise is generated somewhere between the pads and rotors, if you've changed the pads, you're running out of options. Have you tried braking hard first front and then back to see if it is just one brake? I use sintered and while the pads were a bit noisy starting off they're quiet enough now after being bedded in. I tried teflon which were way quieter but had the minor problem of not slowing me down much when I applied the brakes.

Muckers

smacl wrote: »

Given the noise is generated somewhere between the pads and rotors, if you've changed the pads, you're running out of options. Have you tried braking hard first front and then back to see if it is just one brake? I use sintered and while the pads were a bit noisy starting off they're quiet enough now after being bedded in. I tried teflon which were way quieter but had the minor problem of not slowing me down much when I applied the brakes.

No its definitely front and back as I've tried both seperately.

iwillhtfu

Find a long steep hill and roll down it with the brake pads slightly applied the heat will burn out any contaminants. The pads will need to bed in also and it is possible the rotors are fuped.

Muckers

iwillhtfu wrote: »

Find a long steep hill and roll down it with the brake pads slightly applied the heat will burn out any contaminants. The pads will need to bed in also and it is possible the rotors are fuped.

The rotors look fine. Is there anything obvious to look out for regarding the rotors. Any giveaway signs that they need replacing

iwillhtfu

One sign I know of is they go blue this is caused by excess heat and contamination of some description usually oil based. My knowledge of disc brakes wouldn't be great though I usually replace them when I notice I'm blowing through corners more than usual. In your case though I'd say the first pads were contaminated with mucoff or some spray the new set probably just need to bed in properly.

In saying that I assume it's just the usually high pitched squeak when applying pressure and not something binding or loose.

There are old wives tales about baking the pads and rotors in the oven but can't say I've ever considered it.

magicbastarder

what about that trick used with cars of using copper grease on the back of the pads to stop squealing? does that work on bikes?
obviously it might not be easy to do without contaminating the pads.

magicbastarder

iwillhtfu wrote: »

There are old wives tales about baking the pads and rotors in the oven but can't say I've ever considered it.

i have been known to use a heat gun on pads; i suspect it's less faff getting them up to a high heat if you have one.

Cee-Jay-Cee

I changed to resin pads. No more squealing.

Muckers

iwillhtfu wrote: »

One sign I know of is they go blue this is caused by excess heat and contamination of some description usually oil based. My knowledge of disc brakes wouldn't be great though I usually replace them when I notice I'm blowing through corners more than usual. In your case though I'd say the first pads were contaminated with mucoff or some spray the new set probably just need to bed in properly.

In saying that I assume it's just the usually high pitched squeak when applying pressure and not something binding or loose.

There are old wives tales about baking the pads and rotors in the oven but can't say I've ever considered it.

Yep it's just the high pitched squeak. Thanks you've been a great help. Plenty longish steep climbs no too far ftom Tramore for me to do as you suggested.

Muckers

Apologies lads i got it wrong. The old pads and the new ones are Shimano BO1S resin pads. Do the same rules apply?

Muckers

magicbastarder wrote: »

i have been known to use a heat gun on pads; i suspect it's less faff getting them up to a high heat if you have one.

Thats interesting because looking online there and some advice was to heat the pads with a blow torch and to put grease on the back of the pads before refitting them. Also to clean the rotors with Isopropyl alcohol