Help needed bleeding Tektro Draco rear brake

Help please….I have followed the guides but can’t bleed this?
Symptom is I have no lever, just pulls straight to bar.

Reserviour fitted with hose into plastic bag and secured.

Pads out (new ones being fitted) pistons spread by the little block.

Attached the syringe to the bleed nipple, quarter turn on bleed screw and started pushing the syringe, its solid, no amount of pressure will move fluid through, the fluid then leaks from the bleed nipple. The pistons appear to move in the caliper bores but not a huge amount, maybe 2-5mm.

What am I doing wrong?

Thanks

Richard

Hard to say without seeing it but the Draco is a lot like the Auriga which might mean it’s got the same foible about the reservoir bellows… Basically it’s supposed to vent to air on the non-fluid side but it doesn’t do it very well, never a problem when riding but when bleeding it tends to stay inflated and cause problems.

Easy fix if it’s that- you can fit the lever with the blade lowest, take the back cap off the lever (watch out fiddly puny bolts), and basically see what happens.

No promises obviously, there’s some big assumptions in there!

Oh- more basic suggestion, you can’t push fluid from the syringe into teh caliper, can you push it from the brake into the syringe? (ie with lever?)

Northwind thanks. I will have a look at the lever tonight.

No fluid is pushed from lever end either, it just pulls straight to bars, like no pressure in system?

Thanks

Richard

Drawn a blank here any other suggestions?
Thanks
Richard

An educated guess that the piston in the master cylinder is stuck down preventing fluid passing back into the reservoir (or less likely, a badly kinked hose doing the same).

Thanks, I have had both pistons out of the caliper and they appear to move in and out ok?
Really stuck with this one?
Thanks
Richard

Won’t be the caliper pistons, they won’t influence whether you can push fluid from the nipple out through the reservoir. Try disconnecting the hose at the lever, if you can push fluid through then, you’ve eliminated the hose, and pinpointed the master cylinder. A small allen key (2mm ish) inserted into the hose exit may push the piston back, and confirm the problem, though you’ll still need to fix it. A new Deore brake usually looks very tempting about now.

If you do go down the Deore rear route then I have a brand new M615 rear Deore for sale. Email in profile.

tricky dicky – Member

No fluid is pushed from lever end either, it just pulls straight to bars, like no pressure in system?

No fluid in the piston anyway. Hokay, keep it to the absolute basics, if you suck back on the syringe, does it pull fluid out of the caliper? There’s simple but easy to miss things like blocked up nipples that could cause your bleeding problem.

I’m not convinced it’s my diaphragm issue that’s caused your issues so far, tbh, but it’ll still be worth bearing in mind when (if) you get to bleeding it all up.

Firstly Thanks for your input so far all.

In response to Coatsey’s post I tried the allen key down the bore into the master cylinder, not sure what should happen but nothing appears to of moved/unstuck. From the bars end I disconnected the hose from the lever, I can push air through lever entering from hose end exiting from bleed hole on res. I can also push air from lever down the hose to caliper so not the hose?

In response to Northwind
When I use syringe and suck no fluid comes out,blew air through the nipple and all flows freely. Is there some sort of return valve inside the bore where the bleed nipple screws into?

Frustrating!