Why are the present systems different to the older systems? I think it was because the overflow bottle could be made more cheaply as it did not have to be pressurised. I would use the early type as the return valves in the radiator caps commonly fail.

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Chris

Everything I like is either
illegal, immoral or fattening.

just make sure that wherever you mount it, that it is at least partially higher than the top tank of the radiator. air will always migrate to the highest point in the system, so if the tank is lower than the top of the radiator, you get an expansion tank full of water and a radiator with air in it.

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

My daughters sillycar has the o/flow tank down on the subframe way below tha top tank

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David L


My greatest fear in life is that when I die my wife will sell my Mini and tools for the price I told her I paid for them!

Yeah cheaper and it also means that you can top up the coolant when the radiator is still hot.