Tektro Auriga Comp Brake Questions

[surreypete]

Hi

I'm building up a mountain bike ready for when the summer gets here in the UK, I got given a pair of Marzochhi Bomber 55 front forks that came with a Tektro Auriga Comp hydraulic brake.

Wanting to keep the brakes matching I bought a secondhand new old stock rear Tektro Auriga Comp brake, when it arrived it looked in good condition, I had to order a bracket for the frame to allow the caliper to fit with my 180mm rear disc.

Went to fit the caliper over the disc but the pads were out and touching, no worries I thought just push them back in, thing is one of the pistons isn't moving, I've put quite a lot of force on it and it's not budging, the piston looks in very good condition and I can't see any fluid leaking so I'm sure the seal is still good.

I'm thinking it's getting stopped by the hydraulic pressure acting on it so If I open the bleed nipple slightly it might allow it to move, I've never bleed a Tektro, have done a few Shimanos so assume it's the same principle using mineral fluid .

Also if any of you have worked on them I need to ask how you undo the brake line unions on a Tektro? They have a weird spline nut, not seen it before, the bend of the pipe is going away from the frame so I need to undo it slightly and twist it to suit, I'm not wanting to use mole grips as it'll destroy the fitting.

One last question, the newer Tektro I got has a twistable lever, the original is cast as one piece, the newer one is in two, by lever I mean the actual part that bolts to the handlebars that carries the fluid and master piston. How do you change the angle of the cylinder? Is it as simple as loosening the little spline bolt and just twisting it round to where you want it, then tightening the little bolt back up?

Thanks

[BaBaBiker]

Hello.

Did you solve this issue? How much out is (was) it? Do you have a photo?
Sounds like bleeding time. I followed bikeride guide when performing my first bleed this winter: https://www.bikeride.com/bleed-tektro-auriga-comp-disc-brakes/

What I would also try - while you are pushing the piston back in, at the same time try opening the bleed valve a bit.

[surreypete]

I managed to push the piston back into the caliper, it's a twin piston one, started with a knife blade and gradually worked up, I've got it to the point where both pistons are now sitting back in the caliper, didn't have to bleed it or let any pressure off, I've used a coin as a spacer to keep the pads apart for now as I have yet to fix the brake on the bike.

I've also worked out that the pipe union has a cover, you slide that down the pipe which exposes the union nut where it goes into the lever, so hopefully just loosening that off slightly will allow me to adjust the bend on the pipe to sort the run I'm after, also hopefully without letting too much air into the system, I don't mind a bleed if it does