cooling sytems

[keith Portsmore]

Is there any reason why the overflow from the header tank is not fed to an expansion tank so that the coolant can be received on cooling? The standard cooling system runs at 9psi. Is there any reason why the expansion coolant from a heated system cannot be collected by an expansion vessel which will then be drawn back in on cooling. Each time the engine heats it looses say 1 pint of coolant.

Thoughts please - thank you.

[Mark Gordon]

If your car looses a pint each time that it reaches full operating temperature, it's because you keep overfilling it by a pint. The system is designed (as was common in that day) to purge itself of excess coolant by dumping it onto the pavement. Undoubtedly that wouldn't be a design that would be allowed today. Try not refilling the header tank and see if the coolant level doesn't stabilize while the engine temperature remains in its normal operating range.

[rfs1957]

I'm with Keith. I have a plastic bottle zip-tied and nestling in the RH wishbone area and the radiator overflow pipe reaches the bottom of it, because I want to see what comes out of the pipe. Mine loses a couple of cups-full with the heat-soak sometimes, then a few minutes later makes a large burp and sucks it all back up. Great way of seeing what's going on. It doesn't need to be a tank or air-tight, it's just a way of making it clear up its own mess. Am I a Californian and didn't know it ?

[peters3103]

To enable the system to suck the coolant back into the header tank a recovery type cap would need to be fitted, right?

Pete

[PeterCrespin]

To enable the system to suck the coolant back into the header tank a recovery type cap would need to be fitted, right?

Correct, but there's no other pressure type on common sale.

The only alternative you'll find is a blank non-sprung type used for Series 2 radiators etc. these are unsuitable unless your catch tank is pressurised and has a sprung cap, again like Series 2.

... except then you'd want a recovery bottle for your catch tank in case it too burped...

[peters3103]

I have been able to source, here in Australia, a 7lb recovery cap that has the correct length spring for the header tank. I assume that since my original aluminium radiator is long gone and been replaced with a brass unit, an increase to 7lb would be ok.

Pete