I’ve never had a problem with new brakes and I’ve had a lot.
I’ve already got several hope and shimano sets all working well.

I’ve just bought a saint front brake and it will not bed in.
The power is poor and it will not bite.

I’ve even bled the system but that made no difference.

I’ve taken the brake pads out and they have a horrible black coating on them. I’ve used some degreaser to remove this and the brake pads then go a gold colour like before I fitted them.

The brake then squeals like crazy and has more power but after a few brake tests goes back to its normal weak self.

What is this black coating, is it normal?
There was definitely no contamination in the rotor or pads when fitted.

I was expecting a power increase going from XT to saint but so far it’s just been a bad experience.

Anyone got any tips to sort it?

If the brake makes a horrible juddering squeal as the bike rolls to a stop, it’s definitely pad contamination. Send it back.

yep, that definitely doesn’t sound right. send it back and get replacement

Tried cleaning the rotors with brake cleaner + wire wool?

Brake cleaner/degreasers/wire woll will not clean the pads sufficiently.
Burn them with fire (in a well ventilated area) then sand the surface.

If its new, try some new pads to make sure, if they fail to improve things send it back.

I have had this issue on 2 set’s of XT. You do a great bleed, using all the tricks and fit new pads, the brakes feel amazing for a ride or 2 and then start making a terrible noise and loosing all the power. Tried all the cleaning, scouring and re-bleeding tricks but to no avail and the pads get a black film.

I have come to the conclusion that the only possible explanation is a very subtle leaking of mineral oil onto the pads. The most likely culprit is the crimped hose join and the poor way an olive can seat sometimes on the hose.

I know a few people that swear by goodridge hoses for shimano, not because they are any more powerful but because they allow the shimano brakes to fulfill their potential. That’s because goodridge have far superior quality attachments that screw into the hose rather than crimp on with an olive and leak. They also fix the poor consistency that shimano brakes can suffer from which I reckon is also caused by minor fluid leak at the crimp.

Unfortunately goodridge hoses are almost the cost of a whole new brake!!!

Yeah it’s a new brake so maybe there is an issue with the pads.
I just can’t understand this black stuff that is on the pads after a few quick brake tests.

If it was leaking surely if end up with no fluid in eventually. Brake has probably done about 5 miles now and lots of brake testing. It’s just not getting better.

Any fluid leak from the pistons? I’ve suffered from this too many times on shimano brakes.

The black stuff is the same as you find on your chain – a mix of worn metal and grit, ground into a fine paste with oil and pad material.

It doesn’t take much oil or brake fluid to contaminate the pads. Just a tiny drop squeezing out of the caliper centre seam or a seal or pipe union will spread readily with the heat of braking.

weeping piston seals. happens on some shimano brakes. send them back