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I’ve watched the SRAM videos and have checked what I’m doing but I’m none the wiser - can anyone tell me what I’m doing wrong?
I’ve cut and reinstalled a pair of SRAM axs hydraulic brakes. I reinstalled the hoses using the proper sram red olives and barbs.
Where I’m goofing up is on the refilling of the brakes with dot fluid.
I’ve attached the bleeding syringes (both 1/2 full) to the bleed ports on the lever / calliper. Both ports are definitely open but I can’t seem to inject any fluid into the hoses. I’ve removed the syringes, checked the bleed ports are open and that the “clips” on the syringes are both open … but no joy.
It feels like there’s a blockage in the system but the whole set is new so that’s unlikely.
Has anyone else had this problem and if so, how did you fix it?
Thanks!
Are you connected to the correct lever/caliper, not front lever/rear caliper?
Not such a stupid question coatesy but yep, have checked that!
Do you not have to wind back the lever position to guarantee it isn't slightly on and blocking the port in the lever?
Edit: oops, I think that's mtb brakes and you are road, sorry
Do they use the bleeding edge port thingy? Have you tried opening them both a little more and are they both engaged properly.
Carlos - the lever is a screw in type but the calliper is a push in and unscrew 1 turn job.
The fluid drained out of the system fine yesterday but now the cables are shorter I just can’t seem to push any fluid through the hose even with the lower port open 1 turn and the top port open. It’s the same on the front and back brake - all the parts are new so I can’t think what’s causing it.
Bump for the day crowd. Any other bodges that might get the fluid flowing through the hoses again?
Did you drain all of the fluid out of the hose? The title gives the impression that you did, but it wouldn't be the normal way of doing things?
If you have drained all the fuild out then I would start by pushing fuild through from the caliper with the hose not attached to the lever (with care!). Once you have done that then you can bleed as normal.
I was going to suggest the same as Jamz (disconnecting the hose) but if it was me, I'd prob take everything apart and start again
hose not reconnected properly (my guess)
Jamz - yep - and thanks for the suggestion.
The levers and callipers were set up for left hand drive countries so I had to swap both round and then cut the longer tube after putting it through the frame. I can’t bleed either of the brakes so it must be a problem common to both.
I’ll disconnect and try running oil in the tubes then reconnecting. Would I need to change the olives again before doing that or it safe to refit them?
Carlos / soobalias - thanks as well.
Ahh I see - I didn't think of that!
So yes I think the problem will that you have air in the hoses instead of fluid, so first you need to put the fluid back and then you can bleed out any air bubbles that might be left.
Technically you would need to replace the oilves yes, you might get away with not replacing them in practice, I don't know. You can still push the fluid through with the hose attached to the lever and the bleed port open, you'll just have to watch you dont get fluid everywhere when it comes out the lever. In fact you could leave the syringe attached too, if you can fix it vertically with the fluid and plunger removed so that the air can still come out. That way you will be able to see when you have pushed fluid all the way through and then you can back it off a bit and remove the syringe without making a mess (probably).
I think it will be worth fixing the bike in a stand so that the BB is higher than the rear caliper when you do the rear - that way you will have best change of pushing all the air out on the first pass.
You need to have the reach adjusters set with the levers quite close to the bar, in my experience, otherwise fluid won't pass upwards into the master cylinder. This is counter-intuitive, but has solved my issues before.
Additionally, you might find that the piston in the lever (master cylinder) is stuck down. This happens a lot, apparently, and I resolved it by forcing fluid up from the caliper until the piston popped clear. Then clean and re-grease the seals on the piston before reassembly.
Good luck!
Simon1975 - is that reach adjustment trick specific to the sram road levers?
olive fitted wrong way round, I've done that
Ok update as follows:
- the hoses are now filled with fluid. I disconnected the levers and pushed fluid up from the bottom with no issues
- the olives screw on to the barbs so there’s only one way or installing them
- I’ve reconnected the levers and drawn a bit of air out but the bottom syringe oil lever doesn’t change - even when pulling hard on the syringe (bleed port open on the bottom)
- the levers don’t move the pads at all
Aside from taking a hammer to the levers is there anything else I can try? This is literally the first time I’ve failed at home bike fettling in 35 years - is it my lack of skillz or unintuitive design by SRAM?
Further update: just disconnected the hose from both levers and even pushing down very hard on the syringe connected to the bleed port no oil comes out of the connect-a-mi-jig. So even though both levers are brand new there seems to be a blockage in the levers or something else that needs opening in order for oil to move through the brake lever.
Connectamajigs are supposed to self-seal when disconnected, so fluid won't be passing through them. It's beginning to sound like they may not have been fully connected to start with, that could well explain it.
Sounds like the pistons are stuck down.
When you tried to force fluid into the bleed port on the master cylinder, it can't pass the piston no matter how hard you push. It requires movement of the piston to move the fluid. Connect hose to master cylinder, open bleed port, try to push fluid from beneath the piston to free it. You might have better luck if you take off the lever blade.
OK, I'm officially an idiot - someone please put me out of my self created misery.
So the reason my brakes didn't work is because I'd put the olives on the wrong way round. Although I watched quite a few videos that advised to screw them on counter clockwise (which I did) I didn't notice the olive has to go down the hose, not "up".
As it turns out my earlier post was also wrong - there are two ways to screw an olive onto a barb but only one of them works.
Thanks to everyone who took the time to give me their advice - I'll take myself to the corner and will stand there in silence for a few weeks with my hands on my head.
Did you at least enjoy the eureka moment of figuring it out?
I just recently shortened a hose on a Sram brake, I think the threaded olive and barb are very clever. Surely the olive must not have been on the hose and floating off the end of it so the hose was never properly connected to the lever?
And to make you feel better, although I didn't get the olive the wrong way round I did forget to put the olive on the hose before putting the barb in. Then realised I hadn't put the nut on first, then realised I also hadn't put the rubber cover. I got it right on the fourth try.....