Front Brake Issues

[harp]

Hey all, I’m new to the XS650 and just picked one up not to long ago. It is a 1980 Xs650 special, I believe with stock caliper and master cylinder but I am not sure about the brake lines. When I bought it it had a broken front brake with no pressure in the lever. I have tried to bleed it multiple times with no success. I believe the master cylinder is working because I can see the piston moving and when I build pressure just using my thumb I can get it to bleed. When I attached the lines tho there’s no pressure building and the master cylinders not pushing fluid into the lines. I have cleaned all the bolts and shot air through them and the lines. I also rebuilt the caliper to make sure it’s clean and nothings seized down there. Any suggestions on next moves? New Lines? Rebuild mastercylinder? Thanks!

 

[46th Georgia]

Hey all, I’m new to the XS650 and just picked one up not to long ago. It is a 1980 Xs650 special, I believe with stock caliper and master cylinder but I am not sure about the brake lines. When I bought it it had a broken front brake with no pressure in the lever. I have tried to bleed it multiple times with no success. I believe the master cylinder is working because I can see the piston moving and when I build pressure just using my thumb I can get it to bleed. When I attached the lines tho there’s no pressure building and the master cylinders not pushing fluid into the lines. I have cleaned all the bolts and shot air through them and the lines. I also rebuilt the caliper to make sure it’s clean and nothings seized down there. Any suggestions on next moves? New Lines? Rebuild mastercylinder? Thanks!

Try filling the master, put a piece of clear tubing with one end on the bleeder screw and the other end in some type of container to catch the fluid, then crack the bleeder and pump the brake lever. Hold it down and take some tape and tape the lever to the grip. Let it sit overnight and see if any fluid works it's way out. Also, leave the reservoir cap off or at least very loose. If you have fluid in the container the next A.M., close bleeder, fill reservoir and bleed.

 

[motormike]

A brake hose clamp is available.... I've used a small needle nose vise grip.... don't go gonzo on the clamping... but fill the master.... clamp the hose a few inches from the master.... apply the lever... it should be rock hard... if it fades. or doesn't make pressure... the technical term is.... it's toast.....

 

[harp]

Try filling the master, put a piece of clear tubing with one end on the bleeder screw and the other end in some type of container to catch the fluid, then crack the bleeder and pump the brake lever. Hold it down and take some tape and tape the lever to the grip. Let it sit overnight and see if any fluid works it's way out. Also, leave the reservoir cap off or at least very loose. If you have fluid in the container the next A.M., close bleeder, fill reservoir and bleed.

I think I found the issue after trying this. Some leakage from the caliper