Tips needed for dealing with tricky hydraulic disc brakes

check_six

I have a set of Hayes hydraulic disc brakes on my MTB ('05 vintage). I'm having terrible trouble trying to replace the brake pads in the rear brake calipers.

With the front brakes I removed the old pads(HFX shape) and used a 10mm spanner to push the calipers back into their housing to allow enough room to get the new pads in and on to the rotor. However, with the rear brake I can't seem to get enough movement in the calipers to get them pushed back enough to get the new pads in with enough room left over to fit over the rotor.

Can anyone suggest a method for pushing the calipers back far enough to get the new pads in?
If the calipers won't move back, do I need to get a new rear brake?
What would be involved in fitting a new rear brake (I've never tackled a hydraulic brake system before)?

Icyseanfitz

if the piston wont move back enough in the rear caliper you need to bleed it, as for fitting a new rear brake, tis simple much easier than bleeding anyway

langdang

If it's the hfx9 then a good chance its a seized a bit so it won't go back all the way. Maybe strip down the caliper and give the bores a light sanding? They're a bit of pain of a brake when they start to wrong, swapped mine out for Avid Juicy 3s.

Holyboy

langdang wrote: »

If it's the hfx9 then a good chance its a seized a bit so it won't go back all the way. Maybe strip down the caliper and give the bores a light sanding? They're a bit of pain of a brake when they start to wrong, swapped mine out for Avid Juicy 3s.

I would have to agree, Hayes brakes are pants, bin it and replace it with an Avid or Shimano or if you're feeling a bit flush splash out on a Hope!

check_six

Thanks for the info gentlemen. Look like a new brake needs to be purchased. Fetch the swear jar and a ****ing hammer!

Do new hydraulic brakes typically come as a connected up sealed unit so all you have to do is tie them to the bike? Or do they come in bits that need complicated assembly?

Holyboy

check_six wrote: »

Thanks for the info gentlemen. Look like a new brake needs to be purchased. Fetch the swear jar and a ****ing hammer!

Do new hydraulic brakes typically come as a connected up sealed unit so all you have to do is tie them to the bike? Or do they come in bits that need complicated assembly?

They will come fully assembled so very easy to fit, the Avids are flip flop design so can be fitted either right or left depending how the brakes are set up most Shimanos are not so you would need to make sure you order the correct lever with the correct hose length, the hoses usually come fairly long so if you wanted it to be tidy you may need to cut the hose and bleed the brake. I think all that makes sense but I am a bit tired, more coffee I think!

langdang

Holyboy wrote: »

check_six wrote: »

Thanks for the info gentlemen. Look like a new brake needs to be purchased. Fetch the swear jar and a ****ing hammer!

Do new hydraulic brakes typically come as a connected up sealed unit so all you have to do is tie them to the bike? Or do they come in bits that need complicated assembly?

They will come fully assembled so very easy to fit, the Avids are flip flop design so can be fitted either right or left depending how the brakes are set up most Shimanos are not so you would need to make sure you order the correct lever with the correct hose length, the hoses usually come fairly long so if you wanted it to be tidy you may need to cut the hose and bleed the brake. I think all that makes sense but I am a bit tired, more coffee I think!

Sounds right to me holyboy. Hence the need to double check if you are offered a cheap deal on shimanos.

triggermortis

I swapped my Hayes hfx9's for shimano's on my MTB as the Hayes were a nightmare to try and bleed and weren't that good to start with.
As mentioned before, they are handed - ie only fit one way as the reservoir needs to be on top, and they arrived already bled and ready to go, but the hoses were a little long.
I've been meaning to cut down the hoses and neaten it all up, but they've been on there 4 years or so now so I doubt it will get done any time soon

Holyboy

It is possible to swap hoses over on Shimano brakes without bleeding, its a bit tricky though!!