Bleeding! Brakes

[zedhead]

Ok got a 125 enduro style bike.It's Chinese[stop laughing at the back].

Can't get the brakes to work. As it had been standing for a while the front brake was seized on,freed the master cylinder which then started to leak.

I've replaced the mastercylinder with one from a HondaCG125 [same size for the single disc.]

Now the master cylinder works i get pressure when holding thumb over the inlet and no leaks,but no fluid flows down the pipe to the caliper. well a small dribble at best. Is this due to a blockage in the pipe or is there some way of pressurising the system to get the fluid down to the caliper?

In a nutshell

1/ cant get the fluid to travel down into the caliper to create some pressure.

2/Because of 1/ can't bleed the brakes.

3/ Where am i going wrong/

4/ Can anybody guide me to functioning brakes?

Now i have spannered quite a bit on bikes rebuliding from the ground up but i bleeping hate bleeping brakes!!

[Guest]

you are not the only one not fond of bleeding brakes!!

From your post it sounds like a blockage.. but they are unusual. I'm sure you've checked that there are no kinks in the pipe.. You could always try taking the offending pipe off to see if it is blocked??

If you are getting pressure like you say, are you getting feedback in the brake lever itself? That would indicate a build up of pressure.. ie a blockage...

Sorry I can't give you a definitive answer, unfortunately, as you know, brakes are a pain. You just need the time, the inclination and to be methodical.....

[Guest]

check that the pipes outlet on master cylinder ~( where the pipe goes into /connects too)~ connecting has simlar size bore on both cylinders (old & new) as it may be that if different it may be restricting the flow ...

as for blockge in pipe if access to compressed airline blow it through ( take it off the caliper and master )

[rennie]

viewtopic.php?t=13141

see if there's anything in the above link that you haven't tried.

does sound like some sort of blockage to me though.

[zedhead]

Thanks for the advice guys.

Well ichecked everything no blockgages. Then i put my mr obvious hat on and removed the brake caliper.......... seized pistons!! so fluid isn't going anywhere, will remove tomorrow and strip .

[Guest]

booger... at least you know what it is now

[Guest]

my brother in law is a mechanic and when i'd spent weeks trying to bleed my thundercat brakes-he turns up with a bit of old pipe and a syringe and bleeds them by squirting fluid through the bleed nipples-sort of doing it in reverse-trouble is i can't remember how he did it but he did it in 15 minutes!