Radiator cas and gaskets

[milspec]

Pfarber wrote: “ I find it funny that everyone magically seems to recall the level of coolant in their radiators.”

Why is this funny, when you’re checking the coolant level in your truck what you’re really checking for is a leak, since that’s the only way the coolant level could be low. That’s how we all recall the level of coolant. Any time we had to added coolant it was accompanied by the repair of a leak.

[pfarber]

I'm gonna end this with a simple statement:

You CAN, and WILL lose significant amount of water due to a bad radiator cap seal.

You don't have to believe me... how's about this... google something simple like 'losing water out of the radiator cap' and see how many thousands of posts come back.

"Can a bad radiator cap cause overheating?

A bad radiator cap may cause overheating and corrosion to the system as well. The boiling point of coolant is raised by adding pressure to the system. Radiator caps are designed to hold this pressure up to a pre-designed point. When they leak, pressure is lowered and the boiling point of the coolant is lowered as well.

In addition the cap prevents evaporation, spillage and helps prevent air from entering the system. When air enters a cooling system corrosion is greatly increased. Corrosion can quickly eat through a radiator making the problem much worse. Radiator caps can be easily tested and should be replaced at any sign of a problem."

I think ANOTHER issue is that people expect the engine to blow or overheat. Well, you must consider that the GMC270 is a HUGE, good old cast iron engine with insanely low compression, and low RPM. Unlike todays engines that are designed to operate at the edge of the envelope.. the old huffers are not high performance on the bleeding edge motors. So it can, and will run with low coolant. Compare the CCKW radiator to a modern high compression, 300+hp V8. Its the same size! Sometimes even bigger! You have quite a bit of cooling capacity even with the level low.

I don't think I said you would overheat. Just lose water.