Bleeding Brakes

[Simon WS]

Hello there, first time posting etc...
I'd like to say there is a pun intended but having spent the whole day trying to do it I'm not so sure!
I've just bought a '95 Domie that "needs a little work" One area was the brakes - it came with Goodrich hoses that had been fitted but not bled. Rear one went OK but I just can't seem to get fluid to move through the front hose and even get close to trying to rid it of bubbles of air. I even went to the point of taking the front caliper off and raising it above the master cylinder on the basis that air must go upwards but to no avail. I'm now thinking that the master cylinder seals must be sufficiently dry or knackered to not be able to force fluid through the system. It currently looks like something out of Emergency Ward 10 with the caliper strapped up high with tubes coming off in all directions and the lever strapped closed with a tie wrap against the handle bar! I noticed tonight when I went for a late night patient visit that a little brake fluid was leaking down the handle bar cover thingies, so I assume I need a master cylinder repair kit - right? Could a very slight weep stop it from being able to purge air from the system?

Thanks for your indulgence

Simon

[Mervinh]

Take a syringe full of fluid and some pipe attach to bleed nipple blow the fluid back up the system to get it primed, works every time, then just pump away till all the air is gone. be careful brake fluid is a very good paint stripper, wash any spills off with plenty of water.
merv

[Simon WS]

Thanks Merv will try today. Bit worried that the weeping (not mine!) of fluid means knackered seals, but I guess they're not too expensive if they're needed.

Simon

[StumpyFingers]

Could the "WEEPING" be because the caliper is above the master cylinder therefore the fluid is being forced out of the lid.

[Simon WS]

There are some wear marks on the master piston so I've ordered a repair assembly just in case. Interestingly my Honda manual has the diameter of the master wrong (for my bike anyway) it says the piston service limit is 12.64mm and mine was 10.91 (and it's not THAT worn!)
I checked with Wemoto and their parts seem to be the same size as mine.

Simon

[kenny1950]

Try removing the pipe at the mastercylinder and putting you finger over the hole like a valve. Pump it fast until lyou get a good pulse of fluid from the hole. Then refit the pipe and dont let the cylinder go empty and bleed it out. Pump fast it breaks the air into tiny bubbles and it will come out.

Ken

[Simon WS]

Thanks for all your help - got the master cylinder service kit and fitted it and pumped and pumped and thought it wasn't going to work again, but at least it was moving fluid through the system in the end I had to move the caliper around until the last bubbles of air came out and FINALLY I got a firm lever - phew!

Simon