Coolant System Problem - need help?

[Whaler]

Originally posted by chopper


Not sure what type of expansion tank you're running on your Chevy but the Ford FE types have an internal horizontal baffle about halfway up the volume of the tank. The fluid level is brought up to the level of the baffle, leaving an empty space (called the "ullage", FWIW) into which the fluid can expand. Not trying to be cute, but that's why it's called an "expansion tank." It's supposed to have the empty space above the fluid. The expansion comes from thermal expansion of the fluid during normal operation, and also boiling of the coolant in the cylinder heads after shutdown. Most of us who have FEs and live in the warmer climates have some type of recovery tank added to the system to minimize the problems which you have. Make sure you have the later type of radiator cap which has the reverse check valve so that as the engine/coolant cool down, the resulting vacuum will draw the coolant back into the expansion tank.

Just want to confirm this for my self.....I am adding 50/50 coolant to a cold and yet to be flashed up FE with an expansion tank. I assume I am looking for this coolant level as well?

Just to the baffle or slightly above.

Also the thermostat has had a small hole drilled into the top of it, to help out with entrapped air etc. Does a closed thermostat on the cold engine make things any different for me adding coolant. Since I am looking to fill to the running level now?

Thanks

Tim