Anyone got the foolproof method with these things?
Did the SRAM video method 3 times last night to no avail. Lever soft as…

I've got the pistons fully in, de-gassing my fluid and following their instructions to the letter.

Any tips, alternative medicine, ideas gratefully received.

Oh, and when I pump the lever there is a bit of spitting out of the reservoir vent. A clue, maybe?

Cheers.

Is it the same with both brakes? or is one worse?

J3s will always feel soft. It is a budget brake, remember.

I found the 'filling from the caliper whilst holding back/gradually releasing the lever' got rid of the empty feel. Before that, I could pull the lever almost back to the bars despite bleeding as per instructions.

I also tie the lever back overnight as this seems to 'self bleed' the system. Not sure why it works/what is going on but my levers always seem to return to normal after a night being tied up. Anyone know what's actually going on when you do this and why it works?

rolfharris – Member
J3s will always feel soft. It is a budget brake, remember.

Our experiences vary then. I have J5's on one of my bikes, Mono's on the other and I've just (yesterday) installed a set of J3's for a friend. They all feel suitably 'firm' at the lever.

Sorry last tip…. when you think you've pulled all the air out of the caliper, keep going. There's usually loads more of the pesky stuff hiding in there. You have to be quite brutal to get it out (without pulling the syringe plunger out) and I usually give the caliper a few hard taps with a bit of wood to encourage things to move along…

My front brake has a lot of travel but as soon as that has been taken up it is good and hard like my 5s. I haven't touched this yet.

I think the rubber band on the lever puts a "set" on the master cylinder seals so rejouvenating(?) them giving instant pumping untill they relax again.

I'll try the lever sroking while filling from the caliper then, Boblo.

I found mine still very soft after the first time I bled them. All the tapping and vacuuming stuff to get rid of stuborn air bubbles seemed to go on for ever. In fact I suspect that the vacuuming was just drawing more air into the system through the more permeable parts of the syringe/tubing interface wotsitmajig (lets get technical 😉 ). Now I just pump tons of Dot 4 fluid through the system to get rid of excess air, but they're still not the most responsive brakes.

One thing I did do the other day that improved their performance was adjust the levers so they were much further away from the bars. This has made them considerably more userable and means that on long technical descents I can concentrate on the steering and not be distracted by the back of the levers continually coming into contact with my knuckles.

I used to run Juicy 5s on one of my bikes. Right royal PITA they were too! Don't get me wrong, when they worked they rocked but they were *very* high maintenance. As J3s are a more budget version I'd be inclined to get rid and get some Deore to replace them.

Tying the lever back compresses any air in the system, and the smaller bubbles rise through the fluid more easily, when you then pump the lever the air rises through the port into the reservoir. Two problems with this, if you have a high spot in your hose then that's as far as any air will go, and if you pull the lever whilst wheeling the bike on the back wheel(going through stiles etc)the air in the reservoir can find it's way back in to the system again.
If it's spitting back through the vent then you may have a split diaphragm under the cap, and thanks to the design you'll need to remove the lever from the bars to remove and check it.