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mEasy27 10-25-2012 12:11 PM

Not holding Coolant
I made an earlier post about my heat not getting hot and it turned out to be my coolant was low. So i filled the reservoir. about a week later after the truck had been sitting for a couple days, i noticed coolant under the truck.. I checked everything.. water pump was dry all coolant hoses were dry. but it looked like coolant was leaking from somewhere around the reservoir. I'm not sure where though.. all lines were dry. maybe the reservoir cant hold a certain amount of fluid?? not sure. anyone had this before??

snrusnak 10-25-2012 12:26 PM

Did you top off the reservoir?

When the coolant in the radiator gets hot and expands, it builds pressure. At a certain pressure (~14psi IIRC) the radiator cap has a valve that opens and relieves pressure/coolant into the expansion tank(the tank you're talking about). Once the coolant begins to cool down it sucks the coolant(siphon effect) from the expansion tank back into radiator. This system works very well, it keeps the cooling system full(with no air in it) at all times.

This is different than an overflow tank.

If you overfill the expansion tank all the way then when the coolant expands and leaves the radiator it will overflow from the expansion tank(there is an overflow drain). If you under fill the expansion tank you might get some air being sucked into the radiator as the coolant cools and retracts.

Not sure if this is your issue, just giving you some info...

Maddevill 10-25-2012 12:30 PM

I just changed my recovery tank , it had a a small crack right along a seam. Not visible unless you looked at it when hot, then you could see coolant bubbling along the seam.

RamTech 10-25-2012 01:16 PM

A defective cap could be part of the problem. I would recommend pressure testing the entire system along with the cap.

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