My 1980 F150 is not getting fluid to the rear brakes. The bullet valve in the proportion valve appears to be in the middle. I bench bled the master cylinder and still no pressure to the rear brakes. I then unscrewed the rear brake line at the master cylinder and blew about 10 psi of air through the line and I had fluid coming out of the rear bleeder valves. Bad master cylinder perhaps?

 

Are you trying to bleed the brakes? Make sure the self adjusters are backed out all the way, shoes tight as practical against the drum.

 

Yes bleed. There is no fluid even getting to the rear wheel cylinders so the self adjusters wouldn't be the issue.

 

You blew air through the line to the rear. Leave the line off the master cylinder loose by a few threads and get someone to push the pedal to the floor. Did you get fluid? If you did, tell them to hold the pedal to the floor till you tighten up the fitting. If you didn't then something is going on with the master cylinder.

 

I was going to say the same thing.......now


If you get fluid move to the next fitting and do the same. Crack open helper push peddle and if fluid move on down the line till at wheels.


Thing is now that you blew air in the rear lines, yes you know they will flow fluid, they are full of air and will be a bear to bleed.
Dave ----

 

Thanks guys. I didn't want to go the air route but I was it of ideas. I'll get back at it this afternoon and try it out.