Top up radiator or expansion bottle?

[wilf]

Now there's an idea, lol.

[DMT]

It also gives you a 3 sec bulb check when you turn the ignition on, and if there is a fast low level blip the light stays on for 3 secs, so you don't mis it.

[ODProjman]

Interesting thread thanks to all. I have just had the heater matrix on my Stag fixed having got it out myself and put it back too (only one cut finger but a full swear jar).
the Stagweber header tank looks like a sensible idea - my Stag is a Mk 1.5 with a 2.5 PI fitted - does any one have experience of fitting the header to a mongrel set up like this and if so is the fitting kit worth the extra investment. I think it might be just for the air bleed on the filler but it looks like some extra plumbing needed for the “T” piece.