A week ago I replaced a faulty and leaking heater core in my Ram 1500, prior to this the truck would heat up to the point you could bake a cake in it. Now my trk will at times blow hot air(although not as it once did) and other times blow luke warm air. I have replaced the therostate and topped of the fluid levals, still this morning, barley warm air at all. the temp control swicth appears to be working as when turned to the cold position, it gets cold. When turned to the hot side it only gets warm....but at times gets a lil hotter but not like it did...what should I look into next??

 

did ya 'burb' the radiator before ya capped it off? Let it run with the heater on high for a while with the radiator cap off.. and then top it off after it lets all the air outta the system. just a thought..

 

Ill try that and let you guys know.

 

well burping the system worked like a charm, thanks. pulled it up on a steep incline and popped the cap off, let it idle for 30 min and had great heat after that.

 

Well back to more burping I guess. Lost heat this afternoon. How many times do I need to do this??

 

Until you get all the air out.