'00 4.7 low heat

the heater on my daughters "new" durango isnt putting out as much heat as it should. i found the coolant was about a gallon low, and the lower radiator
hose clamp was the culprit. even after topping off the system, its still not producing enough heat for the upcoming montana winter. on the interstate it does fine but as soon as you come to a stop the air temp drops to just a little above warm. its acting like its still low on coolant but the coolant level is fine now. the coolant housing has a bleed hole with a bolt on it, is air lock a common issue? when/how do you use this weep hole? thanks,
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Nathan In Montana
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The little bleed hole is used for getting the air out of the system. Open it up and shut it when coolant starts coming out.
Your description sounds more like a restricted heater core. Is one of the heater hoses a bit cooler that the other one at the firewall? You may need to flush the core and see if you can get some of the gunk out.
Denny
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i disconnected the heater core and flushed it for 15 minutes (both directions) and when i hooked the lines back up and cranked the truck the air was colder than before. i found this to be very odd, and opened my reservoir to find that it was still topped off, despite running the truck for a good 15 minutes after it warmed up. i removed the bleeder screw on the housing and saw the water was low. i pulled the hose to the reservoir off at the cap and blew and it was plugged. after blowing really hard the obstruction finally gave (and splashed anti-freeze all over me) and i hooked it back up. i ran the truck awhile and the reservoir dropped and the truck finally gets hot. although my reservoir was full, the cooling system was ultimatley low.
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Nathan In Montana
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