I am having some trubbel with the brakes on my 2wd crewcab conversion the backs are locking up way to soon. The truck has all new brake parts hoses master and all with drums in the rear that are adjusted with very light drag. The brakes where bleed a few times and there is no air to be found. The fronts are working but not enough I guess. When I try to slow down from highway speed to stoped traffic the rears will almost instantly lock up. I plan on checking the presures but I have not made it that far yet. Any ideas?

 

Sounds like leaky wheel seals.

 

the wheel cylinders are new as of last week and where dry the old shoes looked all chewed up i guess from over heating

 

Which truck is the proportioning valve from?