Originally posted in wrong area. I noticed this is a popular subject and I did look through other post.

I have a 1985 K5 with 305. I bought it a couple of years ago and have been reconnecting all the disconnected wires and hoses ever since.

Right now the heat blows air that is a little warm. The engine was running to cool but after replacing the thermostat twice it is running normal. I hooked the vacuum line back up and the blender door opens and closes. I flushed the heatercore both hoses are hot. The intake hose was coming from the radiator and the out house was going to the manifold. I switched those even though the intake hose is really to big for the outlet on the manafold
I have looked online and in chilton's and Haynes repair manuals and can find nothing on exactly where these heater hoses go.

Any other ideas?

 

My 88 had one hose connected to the right rear of the intake manifold and the other to the radiator. It blew warm air on a good day.
I bought a connector and removed the radiator hose and installed it to the water pump. I now have heat. I just capped off the outlet on the radiator.

 

Yea I would switch the inlet off the radiator. Your not gonna get dick for hot water there.

 

Thanks, yall have pretty much confirmed what I was thinking. I just have to find the outlet on the water pump, I am sure it has been pluged.

 

Ok well thanks for the advise. It made perfect since but $20 in pluggs, fittings, antifreeze and 1 1/2 hours of pulling and refitting hoses while the wife is complaining because I was not finished with my chores. Finished, fixed all the leaks triumphed I swear I heard trumpets playing! Got in to run an erron and turning the heat on on this cold 30's day and........NOTHING! Exactly the same luke warm at best. The heater hoses are very warm and the engine actually runs a little warmer which is fine it is still well with running temp.

I am done messing with the hoses and heater core. I am 90% sure that is not the problem and I know if I continue pulling/replacing hoses I am just going to damage the heater core.

I am going to get back to the blended door and make sure it is closing all the way.

Anyone with other ideas?

 

i ran into a car that was having the same problem. blend door worked, car was getting to operating temperature etc, basically there was a huge air bubble in the heatercore, only causing a little bit of hot water to get in there making the heat just warm. so i just disconnect one hose off the heatercore and one off the engine, put the garden hose to it and blew out the air then quickly put the hose back on the heatercore to contain the water. that worked. d

only problem is then you are letting water into your system so you have to put in some more straight antifreeze to even it out

at work we have a vacuum pump kinda like this



basically it sucks all the air out of the entire cooling system then you flip the valve and it sucks the antifreeze to every corner of the cooling system. never had to bleed a cooling system since we had this thing

 

It has been awhile but I wanted to post the fix for other people in similar situations. The radiator needed to be replaced so I replaced it and had a local garage replace the heater core for me. Not only is the heat working the engine runs at normal operating temp for overall better performance.

Next project duel exhaust.