'95 f150, 302 ac, very little heat comming out of heater. Lots of air, pretty warm at first, then cools down fast. I backflushed the heater core, did get some crap. BUT, when I tried to bleed the heater, for air pocket or air lock, there was only a half stream of water comming out of the hose from the thermostat area, WITH the engine running ! Shouldn't I be getting a full stream of water out, especially if it's running ? Also, is it possible or probable , that there is a resrtiction comming out of the manifold?........ or is there something else that would cause it............Thank You