The pistons on my Hayes HFX9’s on my Orange P7 have seized up and need replacing. Any recommendations as I’ve been out of the loop for a bit? Not sure whether I’d need a discs too or whether the Hayes ones will suffice?

Ditch those old Hayes and get a set of shimano slx. Your Hayes rotors will work fine on them if needed as I’ve got the same set up. Rose cycles used to do the slx brakes at a bargain price

The HFX9 pistons corrode really badly. Well they would if they were not ceramic.

Had to replace mine, and they still like sticking.

Not very impressed.

It was the sticking pistons that made me get rid of my nines tooth

You can get replacement pistons from CRC. I gave up on my Hayes brakes as they just needed too much TLC. Fitted Shimano and never looked back, no more bleeding or sticky pistons.

Hmmmm,

They’re not too bad to take apart and clean. I had HFX9s on my old bike and they were prone to doing this. It’s an easy job to pop the pistons out, clean, re-fit and re-bleed.

BUT – once they start doing this it becomes a more frequent problem.

I got a bit lazy with mine and just replaced them every couple of years when they were on sale at CRC…..

Don’t use them anymore as they are too much of a pain compared to modern equivalents (XT all the way).

Got a 7yr old set of 9s working fine with no issues other than an odd bleed to renew the fluid :
Carrying your bike on the roof or rear carrier exposes any brake unit to the elements 💡 Mine is mostly carried inside the car.
Upgraded to Hayes Prime for this years Alps trip with big discs after reading about the leaking hose and piston seals that were haunting Shimano’s ’12 brakes earlier in the year. Ace brakes, from Merlin btw

Lazgoat, I may have a caliper rebuild kit in my spares box at work. I’ll check tomorrow and if so its yours foc – just email me your address.

Saracendan,that’s a great offer! Email on the way.

Except I can’t see your profile and email address to email you. I’m lazgoat at gmail dot com

otherwise ditch and buys some deores or slx, i bought a load of hayes 9s when they were £30 quid an end from CRC. It was cheaper to replace than bleed and get new pads if not very enviromentally friendly, I gor fed up with the sticking and have replaced with Deores and I’m very happy.

Shimano XT M785’s at £72 and end look seem to be good value, though they don’t include discs.

Ygm

Shimano XT M785’s at £72 and end look seem to be good value, though they don’t include discs.

Yeah, when I was looking for new brakes at the big inning of the year the deals looked good until discs were added. Then there was all the problems with fluid leaks from dodgy hoses and some with dodgy piston seals.
I was upgrading with the intention of going to the Alps where failure is something I did not wish to sample 😉

I opted for the Hayes Prime simply because I have had no issues with my current ones whereas mates have had problems with just about every other make 🙄 + I thought the deal from Merlin was as good if not better 😀