SRAM Guide R lever issue

After cleaning the pistons and bleeding, the front brake lever is on/off with very little lever throw. It’s not at the bar but if I flick it outwards, there’s lots more “travel” than normal. Pulling it on feels like there’s only a couple of mm lever movement and there’s hardly any modulation. Probably a common issue but Googling only brings back the sticky lever issue. It doesn’t return fast, so that could have something to do with it, but I’m not sure. Any help gratefully received.

Sounds very much like a stuck lever piston, it’s blocking the return port to the reservoir, so effectively holding the brake partially on and thus giving a short lever travel and the extra outward throw that you’re experiencing.

Sounds like the same problem I had with my guide RSC. Started to feel like it wasn’t returning quickly enough, no modulation and then eventually the caliper stuck in place and wheel was locked.
Turned out to be the sticky piston in the lever. Brakes were nearly 2 years old and instead of doing the lever rebuild I bought a new brake. 3 weeks later and the other brake did the same but this time I bought a discounted front brake from chain reaction and just swapped the lever and not the whole brake

If you can be bothered/have the time you can rebuild the lever with the updated piston for about 30/40 quid

Ooh ooh, I know this one : it’s a known issue with Guide brake levers. SRAM kind of acknowledge the fault and you might get lucky if outside of warranty with getting modified internals free of charge. You have to send them back to be looked at and fixed, took a couple of weeks for mine if I remember right. Bizarrely they don’t like the heat.

I’ve got a pair of Guide RSCs that came with the bike. I’ve been impressed with the brakes. They’ve been faultless for 3 years but then recently one of the pistons seized in the front brake. So I bought another pair. An updated pair actually with the S4 caliper / bleeding edge port.

I replaced the front brake leaving the old back brake on for now (as I couldn’t face the internal routing). I left the bike out in the sun last month after washing and low and behold the lever became sticky and this has become an intermittent problem.

Unfortunately I bought the new brakes privately (new bike but unwanted brakes) so I couldn’t process under warranty with SRAM UK. They confirmed the part no. I required and I’ve ordered the lever rebuild kit which should arrive today. I’ve also stripped and removed the old brake lever to compare pistons and use as spares.

I rebuilt a set of Guide RS levers with the chinese aluminum pistons. £13 for both sides via Ebay. Took a couple of weeks for the parts to arrive. Easy to do, takes 5-10 mins with the right circlip pliers. Much nicer action afterwards. I have 2 sets of Guide R to do next.