I’m bleeding my Sram Guide R’s using a TBS bleed kit. They’re pre-2016 so don’t have the bleeding edge port.

Anyway the front brake was bled fine and I have also bled a friends Guide T this week so I understand the process.

However, when bleeding my rear brake, I cannot get a strong bleed. When the syringes are connected with the hose clamps in place the lever feels firm and normal, but when I have removed the syringes and screwed in the bleed port bolts, all pressure is lost and the lever goes to the bar.

I’m loosing some fluid when disconnecting the syringes from the lever/caliper but this happened on the other brakes too and they’re fine.

I’ve tried both the standard Sram bleed procedure (on YouTube), along with a more conventional bleed with an open container. Both have the same result, so I’m lost. I’ve checked the brake hose, lever and caliper for leaks and it all looks fine.

I am tempted to disconnect everything, empty all the fluid and start fresh. But the amount of times I’ve bled this brake I would have thought any air bubble would have moved. This happens with the brakes being bled on and off the bike, and i’ve tried the bike in various orientations in the stand too. I do get a slight leak out of the bleed hose if I pressureise the system, shut the hose clamps and then pull the lever which is annoying but again, the other brakes which I done are fine.

Any suggestions would be great! This is for my old Stanton Slackline which I’m rebuilding for my GF. I’m tempted to cut my loses and get some Hopes but I really want to solve this issue first.

I’m thinking of maybe trying to bleed with the pistons pushed out, then closing off the caliper port, removing the lever syringe and pushing the pistons back. Howvever I can’t get the 4 pistons to move out of the caliper as the system has no pressure or leaks slightly with the bleed kit attached!!

Are the pistons moving out freely and equally? If so, I’d check:

1) your syringes and bleed hoses, and make sure they have a really good seal else you’ll get nowhere. It sounds to me like you’re drawing air in that way. I had the same problem, and I ‘invested’ in some cheap turkey-baster style ones recently from Amazon, and with the correct O-ring in place they make all the difference- I can pull out on the syringes with the correct force needed to pull air bubbles out and no air or fluid gets past.

The front/back thing is because of the hose length. The short front hose doesn’t need much pressure to get a good bleed, whereas the rear one does, which shows up the limitations of your bleed kit.

2)the reach adjustment, if fitted. Wind it all the way out on the rear lever to make sure its working freely, and then back in (I think for ‘R’ its 80mm).

3)If that fails, clamp the lever and leave it overnight, with the lever vertically above the calliper.

Sticky pistons can also make the brakes feel like there’s air in the system.
My rear (brake 😉 ) has been spongy all week, all 4 pistons move in and out when pulling the lever but not enough to unstick themselves from the seals. I’ve bought a piston release tool from r3pro and used it to unstick all 4 pistons, clean them and lube them with a little red rubber grease. Lever has gone from pulling back to the bar to rock solid with minimal lever travel (better then they’ve ever been if I’m honest) without bleeding the system (I’d done it a couple of months ago so knew it should be fine)

Have the same brakes from 2015 and the rear is quite tricky to get right. I ended up over filling the system so the pistons stuck out about 2mm each. Then, after removing the bleed kit and closing the system, pushed the pistons back. Been much better since.

Thanks for the replies everyone 🙂

The bleed kit is the TBS one from eBay – It seemed to be well reviewed but crucially a lot cheaper than the real Sram one. These were parts bin brakes so I didnt want to invest a lot in them. I’ve done the DIY lever refurbishment at home now so I want to get them working! As I said however, it does leak at the connection between the hose and the screw in fitting, so I will try address this tomorrow.

Fair comment about the longer hose, it is going to be the trickier brake to bleed… But I bled my mates Guide T rear brake fine first time which had all been disconnected and re-hosed so it was full of air.

I followed the Sram vid so the reach adjustment was wound out. I did think about trying the lever cabletied overnight trick – That’s solved a few problems with brakes before!

Good to see the R3PRO tool worked – I will model and print myself one tomorrow. Looking at their site, it’s reminded me to print a caliper alignment tool for my Hope E4’s which I haven’t got round to yet. Some interesting stuff on that site, I’ve done my own GoPro mounts which we used on our formula racecar which worked a treat too!

Think my plan will be to try seal the bleed kit, push the pistons out with my own printed tool, then lube and reinstall before bleeding. If that doesn’t work i’ll try trick the system by having the pistons pushed out a few more. And… If that fails I might have to get some more Hopes ordered. The simple traditional bleed procedure on them combined with their reliability, serviceability and incredible performance makes them hard to fault!