Brake problem

[whitey1j0]

The front brake on my '73 ironhead, which is a single disc,when applied slowly,the lever bottoms out, and I have no brakes, if I apply it quick, it works fine, I rebuilt the master cylinder, and bled the brakes at least 10 times, and nothing is leaking, any input would be greatly appreciated, Thanks Whitey

[Chris Haynes]

If you honed the master cylinder you ruined it. They have a tapered bore from the factory.

[whitey1j0]

Thanks Chris, that's a good thing to know, but I didn't hone it, I just used fine Scotch Brite to clean it, and it was doing the same thing, only worst before I rebuilt it

[rwm]

this would happen a lot on my quad.every time i worked on the brakes.they just never bleed right. the air bubble want to go up not down through the caliper and out.i would stand it up on the rear tires so the front were 4feet off the ground and higher then the master cylinder. that worked like a charm for the front.it was to hard to do for the back.anyway i saw a hand held vacuum bleeder at an auto parts store. i think at the time it was less then $30.00. that beat the hell out standing the quad up.makes the whole thing a 1 person job.

[Robert Luland]

The tool you are refering to Rob, is called a Mighty-Vac or as I call it "priceless".

[whitey1j0]

Thanks for all the input, I just now got around to working on it, it turned out I bought a rebuild kit on ebay for 11 bucks and the "O" ring and plunger were about .010 undersize, I bought a kit from HD, and it's working perfect