'T'/tee fittings in heater hoses

[InfInIty13X]

My heater hoses are not hot. Not the one from the head, not the ones from the firewall, none of them. Therefore I have no heat in my car (and the temp here in AL dropped down to the lowest we've seen in three years: 14° F.) I am 'hoping' that it's just air in the system, although I am not overheating thanks to BillyM. :D

What I need to know is what hose to put the 'T'/tee fitting in; do I use the hose coming from the head to the HCV or the hose running from the HCV into the firewall? It's one of those Prestone Flush 'N Fill Kits and I'm going to use the 3/4 fitting hoping it is sized right. Then, what do I do if the hose can't clear out the heater core assuming it's blocked? Is there a solvent I can pour in there or...

[redandrusty]

I would guess your heater control valve is stuck closed. Make sure you're getting vacuum to the valve or put a mitivac on it and see if it moves/opens. I've never heard of the core being blocked.

If you're taking hoses off you might want to see if you can bypass the HCV and see if hot coolant flow. Just buy the appropiate barbed fitting and connect hoses end to end. usually available as a generic part in auto supply stores.

Also, I used to put those Prestone T's on my car and twice they failed and I lost coolant/overheated. The plastic just deteriorates and cracks. I wouldn't use them. Not worth cutting the hose.

[InfInIty13X]

Do I just pull that tiny vacuum hose off the top of the HCV and feel for suction with my finger? I would like to keep the climate control if possible so I don't want to bypass the HCV (although I have to weigh my pros and cons in that case.) I don't know where I could find access to a mityvac, and I really don't want to buy one just for this.