Hi,

My guide r brake has died. It either needs a new piston kit or replacing. It pulled to the bars on saturdays ride. On bleeding it refuses to allow brake fluid from the caliper to move to the piston. after much dot fluid all over the floor I a fairly certain something is stopping fluid moving in the piston. I tried stripping it down, but as I don’t have the correct circlip pliers I cant get the piston out.

So as I cant find the piston kits online its either

£85 for a guide rs.
£80 for a xt m800
~£65 for an slx700

or a pair of second hand guide rs.

Any suggestions? Thanks!

https://www.bike-components.de/en/SRAM/Guide-R-RS-B1-S4-Brake-Caliper-Spare-Parts-2017-p54857/

Thanks!

Unfortunately it’s the piston in the break lever. I think it’s possible to buy every other internal bit from bike discount except the one I need.

Bah!

I saw somewhere that this might be due to the piston swelling up. It just needs a light sanding and maybe a new o ring . Buying a set of circlip pilers and trying that will be a lot cheaper. Good luck

You’ll need to adjust the bite point adjuster, if is full wound in then you can’t push fluid up from the caliper

Guide r doesn’t have a bite contact point adjuster. All it has is a reach adjuster.

Lever internals

https://www.amazon.co.uk/Assembly-Aluminium-Hinged-Compatible-11-5018-004-028/dp/B01N8WLHJV

https://www.amazon.co.uk/Assembly-Aluminium-Hinged-Compatible-11-5018-004-028/dp/B01N8WLHJV

send it back, they have a 2 year warranty, mine failed last week, same issue.

just remember if you switch brake brands you may need a matchmaker for the sram shifter.

i hadnt planned to buy another sram brake, but the adaptor seems sold out on a few sites or £30, so easiest option (seen as ardrock is only a few days away) for me was a straight replacement.

i was gutted yesterday when it arrived and the front brake from crc appeared to be a left handed as it was ziptied in the box,
i rang crc and the nice lady said oh those brakes are ambidextrous, just turn it upside down :0)

Thanks whatyadoinsucka. Unfoutunately it is an ex demo bike and had a 3 month component warranty (which I thought was pretty fair).

Thanks for the link BoardinBob. It was the seller dispactes within 1 to 2 months that put me off ordering it.

I’m going to swap a brake off an unused bike and wait for a cheap replacement lever to come up.

Cheers all

The bikes’ warranty shouldn’t affect SRAM’s two year international warranty. That should still be good although could reasonably be taken from the bikes’ ‘in service’ date as a demo bike not the point you bought it. A limited warranty as you quoted will just be the liability the seller is happy to accept. They can’t revoke SRAMs warranty although they can provide extra cover if they wish.

Well in that case I’ll give the folk I bought the bike from a ring 🙂

FWIW I’ve done the same to my front Guide R in the alps. Lever sticking in and the reach adjuster buggered. Had to buy a new brake when I was out there, and the broken one is going back to the shop for a warranty claim as the bike is <2 years old. It’s a well known problem.