brake problem

[bigwoody]

I am rebuilding a rusty old wagon (87). I had to drop the gas tank to fix the frame. While it was down I redid all the brakes. New calipers and wheel cylinders. All new brake lines coming out of the proportioning valve to the wheels. The 2 from the MC to the valve looked good so I let then alone. I bled them and thought i was done..

After i got the tank and everything back together I started it up and the brakes went to the floor. So I bled them again, still to the floor. Figured the master cylinder was bad after all its been sitting for close 8 years I'm guessing. I put the master cylinder on and bled the system again. Still went to the floor.

If i pump the brakes with the engine off can get a fairly stiff pedal but soon as it is running the pedal goes to the floor. With everything new and no oil leaking out I would think it would be air in the line. I am pretty sure i bled them thoroughly. Right now I'm stumped

[Chrome]

When you replace that much of the brake system it will take some work to get all the air out. Also, double check all fittings to make sure they are good and tight.

[bigwoody]

I bled them some more. I didnt see any air and still no pedal when its running

[chakaD460]

You bench bled the MC, right?

It will take forever to bleed properly if you didn't. You started at the farthest point and bleed forward, right?

I would just keep bleeding. There is an air bubble trapped somewhere in the lines. Most likely the back.

[andy d]

you have a connection in the lines some where that is sucking in air. Until it is found and fixed, you can replace good parts and bleed the brakes until he!! freezes over, you wont get a good pedal. I have never had to replace an MC or the proportioning valve a grand wag, but Ive run into this problem a few times. Always the same solution, a coupling needed just a bit more tight to seal.

[james1414d]

unadjusted rear brakes? I assume you tore them down to do the wheel cyls. something to check anyway.