Master Cylinder Problem

[alex1roy]

Hi.

I had a problem with my front brakes. I didnt have much pressure when i pulled the breal handle. So at first a thought it was the break oil since i just hd bought the bike. (its a 2002 kx 250). So i bled the brakes, and nothing changed. then i ordered a repair kit because someone i know told me the seal were done. So changed the seals and now i have zero pressure. no brakes at all. I cant even bleed them because the is no pressure at all. it was an All Ball Racing repair kit.
Anyone know what i could of done wrong or what went wrong so i can fix it and go back riding ?

[bjunior]

Yes could have cut seals in cylinder also maybe put Teflon tape around bleed screw. I have found out front brakes harder to bleed try multivac?On bleed screw u need a tight seal with hose around screw. its leaking air some where.

[cowboyona426]

I would go back over what was rebuilt and make sure all the seals are correctly installed and not torn. You said you rebuilt the master cylinder but didn't mention the caliper - that might be where your problem is. Make sure the pistons aren't stuck in the caliper. When you get ready to bleed it again, try forcing fluid up from the caliper through the bleed screw using a syringe because trying to bleed from the top down doesn't always seem to do the trick. Once you get a good firm pull on the brake lever pull it in as much as you can and zip-tie it to the handlebars overnight so any remaining air bubbles can work their way out.

[Moto7man]

Also, try to back the adjustment screw on your lever that actuates your master cylinder, then pump the lever. Sometimes the greater lever travel will allow master cylinder to prime itself and it will firm up quickly.