antifreeze question. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1tonchevy · 02-21-2011, 04:31 PM

So i did the therma stat an fixed a leaking heater core hose. and filled up my rad as i normally do top it up after completing work,let run with rad cap off and top up as neeed till it "burps" or opens T stat and fill till full. so with it full i put the rad cap on an jobs done. but if i go for a drive or even just let it sit the level in the rad drops not alot but enough to top it up.

The thing is it's not going in the oil, it's not leaking any where that i can see, not dripping on the ground,heater works awsome, and it's not going in the cylenders (i'm assuming as the exhaust is not smoking)

So where is it going? :S

Thanks Dru

tucsonjwt · 02-21-2011, 07:03 PM

How is the level in the overflow tank? When I have had this condition twice in the past it was a slight crack in the overflow tank. The coolant can puddle up a bit under the tank before it drips off, and if you are driving it will blow off the truck quickly. The hose from the radiator to the overflow tank can also be leaking. Of course, all hoses are suspect, as is the water outlet on the intake manifold. Hoses leaking at the attachment to the engine are hard to find because the coolant evaporates when it hits the hot engine - look for discoloration or water stains around where the hose attaches. Good Luck.

tucsonjwt · 02-21-2011, 07:13 PM

One more thing - the nipples from the heater at the firewall can become distorted due to over tightening the radiator clamps. The nipple becomes oval shaped or even kinked and the hose will not seal tightly. Usually, you can carefully "reround" the nipples with a screwdriver/socket/metal rod etc. This seems to be a problem with the aluminum heater cores more than the copper ones.

1tonchevy · 02-21-2011, 07:30 PM

Quote:

Originally Posted by tucsonjwt

One more thing - the nipples from the heater at the firewall can become distorted due to over tightening the radiator clamps. The nipple becomes oval shaped or even kinked and the hose will not seal tightly. Usually, you can carefully "reround" the nipples with a screwdriver/socket/metal rod etc. This seems to be a problem with the aluminum heater cores more than the copper ones.

Thanks i'll take a peek at the mentioned above... i'm leanign towards it being the overflow tank as it's seen better days.

02-21-2011, 04:31 PM	#1
1tonchevy C35 Crew Dually Join Date: Nov 2008 Location: Belleville Ontario Posts: 1,116	antifreeze question. So i did the therma stat an fixed a leaking heater core hose. and filled up my rad as i normally do top it up after completing work,let run with rad cap off and top up as neeed till it "burps" or opens T stat and fill till full. so with it full i put the rad cap on an jobs done. but if i go for a drive or even just let it sit the level in the rad drops not alot but enough to top it up. The thing is it's not going in the oil, it's not leaking any where that i can see, not dripping on the ground,heater works awsome, and it's not going in the cylenders (i'm assuming as the exhaust is not smoking) So where is it going? :S Thanks Dru __________________ If it aint square, I don't care. 84 C35 CC Dually Project log... http://67-72chevytrucks.com/vboard/s...d.php?t=414892

02-21-2011, 07:03 PM	#2
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,188	Re: antifreeze question. How is the level in the overflow tank? When I have had this condition twice in the past it was a slight crack in the overflow tank. The coolant can puddle up a bit under the tank before it drips off, and if you are driving it will blow off the truck quickly. The hose from the radiator to the overflow tank can also be leaking. Of course, all hoses are suspect, as is the water outlet on the intake manifold. Hoses leaking at the attachment to the engine are hard to find because the coolant evaporates when it hits the hot engine - look for discoloration or water stains around where the hose attaches. Good Luck.

02-21-2011, 07:13 PM	#3
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,188	Re: antifreeze question. One more thing - the nipples from the heater at the firewall can become distorted due to over tightening the radiator clamps. The nipple becomes oval shaped or even kinked and the hose will not seal tightly. Usually, you can carefully "reround" the nipples with a screwdriver/socket/metal rod etc. This seems to be a problem with the aluminum heater cores more than the copper ones.



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