Brake problem question

[5150 will]

O.K. so I removed the proportioning valve and needless to say, it had quite a bit of crap in it. My question for those who know. When I remove the end caps and springs inside, is the center section where the sensor rod goes supposed to move back and forth at all? Mine doesn't seem to and I don't want to force it if it's not supposed to move.

[ZCurves]

O.K. so I removed the proportioning valve and needless to say, it had quite a bit of crap in it. My question for those who know. When I remove the end caps and springs inside, is the center section where the sensor rod goes supposed to move back and forth at all? Mine doesn't seem to and I don't want to force it if it's not supposed to move.

Yes, the rod is supposed to move back and forth. Just clean up the rod and spring and make sure the passages are not plugged up with crud.

TIPZ:

• When working with brake lines and fittings on old cars, chase the threads with a TAP/DIE to clean them. This will make for a tighter fit during re-assembly.
  
• Check the the Flared Fittings and buff with sandpaper if dirty.
  
• You can use Lawn Trimmer line to clean the insides of Hard Lines.
  
• Use only wrenches designed for Flared Fittings.
  
• Never leave Brake Cleaner or any solvent in the system -its hard on the seals.
  
• Use compressed air to clear the crud, followed by clean Brake Fluid.
  
• Finally, when you are completely done working on the car, rinse everything off with some soapy water. Brake Fluid and Paint do not get along very well.
  

I am attaching a pic of the Proportioning Valve from the 78 FSM to give you a visual, I suggest you find the corresponding one for your year model.

Good Luck!

[5150 will]

I think I'm getting closer. I got all the guts of the proportioning valve out and discovered a bunch more crap in there and the shaft inside was stuck pretty good. For those that don't know, inside, on each end behind the main caps and springs there are a couple cone looking separators that look like the end of a fuel injector with a needle size hole in them. In between these is a barbell shaped rod with o-rings that moves back and forth I assume based on pressure to the front and rear brakes. It wouldn't take much to clog these in a car that has sat for a long period of time, so when doing a refreshstoration do yourself a favor and tear into the proportioning valve when going through the brakes.

The pedal already feels more proper after bleeding the master again. Once I get them bled completely again, I'll let you guys know what the status is. Thanks again for all the help!

[Bruce Palmer]

But no wire comes off of this piece that you are getting all cleaned out?

Thinking back to that siuation where one circuit wasn't applying pressure, the pedal was rock hard and after I fixed the problem to where both fronts and rears were working again the pedal softened up to correct feeling.

Edited December 10, 2010 by Bruce Palmer

[5150 will]

Bruce, yes there is one wire that attaches to the top of mine.

[5150 will]

Many thanks to all who helped me out on this AND the Search function. The Winner is.............Nigel. The Reaction Disc had fallen out from behind the booster rod. I think I know why they call it a reaction disc. I got every kind of reaction you could imagine when everything I tried for a week plus didn't work:mad:. I may have even made up a few new words that probably aren't suitable for this forum. Anyway, BIG THANKS again and you guys rock!

Will