Less coolant = less pressure in system?

[Simon S]

Last fall when I put some run time on my m42 and bled the system - I noticed (at the time) that my coolant level was ~1cm below the ‘cold’ mark on the radiator’s reservoir tank. It ran and held temperature fine.

Since then, I swapped in a new radiator, bled, etc. – and now the level is bang on the cold mark.

My theory is that with more air in the system – the system’s overall pressure would be lower. (air compresses easier than liquid)

I’d like to keep lower pressure in the system in hopes that the reduced pressure would help my heater core live longer before I get around to replacing it proactively.

Thoughts on this? I’m considering draining out some coolant to that low level..

[Dj Buttchug]

hmmm interesting concept... i would think the least amount of coolant would fall somewhere near the cold mark.

the less coolant you have the harder/ longer it takes the system to pressurize. Not sure if such a small difference in coolant level would make much difference in the system pressure

[Simon S]

10-4
I'll just leave it as is then.