Help with bleeding tektro brakes please

Hi
One bled fine – syringe on the bleed nipple at the caliper end but the other will not bleed thru. I have disconnected the brake line from the lever end and fluid will force thru from the caliper to the end of the line but it will not go into the lever. I can suck fluid out of the bleed port in the lever so that is clear as well. I do not understand what is going wrong why it will not reverse bleed

any thoughts?

Ta

I usually bleed the tektro’s at work from the top like hopes. Worth a try

mine bled bottom up fine, so odd – have you tried pumping lever with hose disconnected ?

If they are anything like mine were you would get better performance from throwing them over a wall and doing stoppies with your feet 😆

I bled my tektro recently, didnt follow instructions though.

A. Turn lever on bar so reservoir lid horizontal
B. Remove res. Lid and seal
C. Open bleed nipple on caliper. Fluid should run out and res level will fall. If it doesnt, bleed port in mastercylinder might be blocked. if the bottom of the res. Is full of leaves and gravel, clean it out and try thru bleeding again.

Which Tektros? Auriga Comps have an official bleed tool and method which doesn’t work well, so I always do them like porter_jamie describes, which works very well (as long as you don’t round the little bolts, they’re not really designed for regular removal)

auriga comps.

I think its a port in the master cylinder is blocked – I have now stripped them down – ruddy fiddle getting the circlip back in

right – completly baffled now.

Stripped the mastery cylinder down to its components – all drillings are clear. The return port is clear but while it is a 1mm drilling in the reservoir side its only a pinhole on the master cylinder side.

However when its assembled the seal of the master cylinder piston seems to cover the return port which is why it will not bleed either direction or pull fluid thru from the reservoir to the master cylinder.

Any bright ideas?

they are second hand but looked like they had never been bled

Chack the piston retaining washer and circlip aren’t distorted, if they’re bent it can hold the piston too far in.
Edit. Could the previous owner have fitted the incorrect piston assembly from a different Tektro brake?

retaining washer and circlip are fine.

Previous owner says he never did anything to them. lever was coming back to the bar so bled by his LBS and okish after that. old as a working front and a dodgy rear with a kinked hose and a sticky piston he thought for much cheapness so no complaints

I have got it working by filling all components with fluid and forcing a bit in from the top. However its effectively a closed system now.

Wrong piston assembly sounds plausible

strange. the bleed port should only be open when the lever is fully released – is there something stopping the piston and or lever returning fully?

also, has someone accidentally used normal brake fluid not mineral oil? i have visited a couple of automotive clutch actuation suppliers in germany, and they showed me round the labs. if the seals see any of the wrong type of fluid, the seals swell, and fail.

i wonder if the other lever is exactly the same? also, is there any data or pdf’s online?

i probably should strip my rear tektro – post a pic up of yours in case it is the same.

My Auriga Comps were pretty easy to bleed (done it several times as they sprung a piston leak). Remove nipple on caliper and attach hose. Remove bleed nut on the lever, and insert hose for less mess. Then loosen the bleed port with the hose attached on the caliper and push your new fluid through with a syringe.

That was along the lines of how I done it.