Could some one explain the difference. I'm using a polo radiator on a cross flow with no heater. Do I need and expansion tank (pressurised system) or a header tank (for filling radiator) or have I got these the wrong way round or I am just showing how stupid I am

Thanks

hi my locost is running a 1640 xflow and has no heater no expansion tank and no header tank. if that helps??

Cheers

Brian

Wrong way round - but I won't hold it against you! I've been bothered by this over the past month or so.

There are 3 ways of dealing with this:

1. Just leave an airspace at the top of the system and don't have any tank (like Brian described). This wouldn't work for me due to the layout of the plumbing (If I left an airspace my fan switch would be out of the water).

2. Have an expansion bottle (unpressurised) that takes the overflow from a completely full system, and sucks it back when the engine cools. Worked for me for a while, but suffers when you get persistent airlocks. You need a particular kind of pressure cap for this - it has a return valve to allow "suck back" (ooer, missus! )

3. Have a pressurised expansion tank - bit more plumbing, but makes shifting airlocks much easier. Tends to run at a higher pressure as well - don't know if that's good or bad! Everyone's told me that they have very few problems when this system is used.

Hope this helps!

David

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Originally posted by richyo
Could some one explain the difference. I'm using a polo radiator on a cross flow with no heater. Do I need and expansion tank (pressurised system) or a header tank (for filling radiator) or have I got these the wrong way round or I am just showing how stupid I am

Thanks

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