Klr 250 front brakes problem?

Question

The front brakes on my '95 Klr 250 are not working, they pull in only a tiny bit, and there is no weight in the lever. i tried changing the fluid and bleeding them, and i think i did it right but they still don't work. the pads are good, and i checked the line connections. could they maybe need a rebuild or something drastic like that? or am i missing something?

Answer 1

when the lines are empty, the master cylinder doesn't create enough vacuum to force the brake fluid through the system.

its easiest to bleed the brakes if you make a pump out of a big syringe and some clear tubing.  you can get a big plastic syringe at a tractor supply or similar store (made to feed livestock)

connect one end of the tubing to the syringe and the other end to the brake bleeder nipple, with the nipple in the open position.  

fill the syringe with brake fluid and pump it through the brake bleeder nipple from the caliper up, until bubbles stop coming out of the reservoir.  you can also fill the reservoir and suck the BF through to the caliper until bubbles stop coming out into the tubing

Answer 2

To check the master cylinder, take a small piece of cardboard and a pair of vice grips (mole grips). Wrap the card around the brake hose as close to the master cylinder as possible (this is to protect the hose). Use the vice grips on the brake hose (over the cardboard) as tight as you can make them. You have now stopped the fluid flowing from the master cylinder and when you squeeze the brake lever it should be ROCK HARD! If it isn't then your master cylinder is faulty and needs rebuilding. If it isn't faulty you need to check the brake piston in the caliper is moving freely. If it's got twin pistons in the caliper and one piston is sticking, it will make the brakes feel very spongy and soft. Get the other piston moving freely then try again. Good luck.

Answer 3

No weight in the lever makes me think you need the master cylinder rebuilt.

Answer 4

To check if you need a master cylinder rebuild -

Remove the brake hose from the master cylinder and press your finger over the hole.

Pump the lever.

If the MC is in working condition, the pressure will push your finger off the hole.

If the MC is good, bleed the brakes from the large bolts of the brake hose, then bleed from the bleeder valve.