I am losing coolant and cannot find out where it is going...

Good morning and welcome to just answer. My name is \*\*\*\*\* \*\*\*\*\* I will assist you today. I am sorry you are having this coolant loss problem, but I will do my best to help. First off, have you had the cooling system pressure tested using a cooling system pressure tester? Chris

For further info, I have (in the past year) replaced tstat, tstat housing, radiator, upper and lower hoses, all clamps, water pump, and in and out heater core hoses. Everytime I find the source of the leak and fix it, two days later I am leaking again.I have had it pressure tested. We raised it all the way to 15 or so pounds and saw no visible leaks, but did see a gradual and slow leak in pressure.

Okay, if there are no more visible leaks while under pressure, you may have a slight leak due to a failing head gasket or crack in a cylinder head. How often do you have to add coolant? Chris

At this very moment, I am losing about a half-gallon every two-three days.

That's a lot. Let's get a chemical block tester kit and check to see if there are hydrocarbons in the cooling system which would indicate an internal leak. Have you used one of those kits before? Chris

I have not, but they have been recommended to me before.

Okay, let's try that, and then let me know the results. Click on the link to see one of the kits: https://www.harborfreight.com/combustion-leak-detector-64814.html?cid=paid\_google|||64814&utm\_source=google&utm\_medium=cpc&utm\_campaign=&utm\_content=&gclid=Cj0KCQiA0-6ABhDMARIsAFVdQv-FhRfqDTXZRohQTXvASru16oLXUEMtnqWmFYVaI9oWjp1QssHbDv8aAv7NEALw\_wcB

The one time that it was recommended, it turned out that the problem was a leak in the radiator, (above oil coiler) so I assumed I had fixed the problem.Also, how accurate are these kits? I would love to use one, but I would rather not have a "false positive" if that is even possible.

They are actually pretty accurate.

Sounds good. I will go pick one up today and see what I can find. Assuming it is a head gasket, I know those are pretty costly but can be prepared. Is there anything you can do for a crack in a cylinder head?

Well the correct repair for a cracked cylinder head is to remove and replace or have the head sent out for repair. However there are products on the market that can "seal" a crack like Blue Devil. But that is sort of a "cheat" way to repair it. Let me know how it goes and thanks again for using just answer! Chris

Thanks for your help! If all goes sour I could be asking for help on installing a 5.3 or 6.0 in the rig. lol

You are very welcome! Thanks again and do keep me posted. Chris

Hello again. I tried the block tester kit and got no bad results. I work at a logistics company so I took the truck to our shop and let the mechanics look at it afterwards, and there is no sign of leaking after pressure test. They think it is internal (which is also what you said), so I am going to take it to a radiator shop today.

Okay, well that is good news about the block test at least. Let me know what the shop says. Chris

Will do. My plan is to let them evaluate and see what is wrong and then fix the problem myself if it is not too terrible.

That sounds like a very good plan! Chris