[Fot] TR4 expansion tank question

[Randall]

> Expansion tank - tank that is under pressure and keeps extra coolant in
> store. Needs to be the highest spot of the system.
> 
> Overflow bottle - catches the forced out water. Needs to be lower than
> the filler cap.

I agree on the definition of expansion vs overflow (aka recovery).

But, while it is better/easier to have the expansion tank at the top; it can
still work mounted lower.  One example is the later (73 onwards) Triumph
Stag, which had an expansion tank mounted near the bottom of the radiator.
The downside of having it down there is that you cannot use its cap to fill
the system (the Stag has a separate filler cap without a pressure relief),
and you cannot tell if the system is leaking (or is full) by the level in
the expansion tank.

The Stag's expansion tank was attached to the radiator by a small tube
running to the top of the LH radiator tank, so any small amount of
accumulated air would tend to find its way into the bottle as the system
warmed up.

-- Randall