I am using a Renault radiator in my car and want to use the hole meant for the fan switch as an inlet for the expansion tank.

Is there such a thing before I try and make one, I will struggle with the 22 mm thread.

Cheers

Adrian

Get a 22mm x 1.5mm blanking plug and then drill/tap it for whatever adapter you want?

Hi Steve thanks for the idea, are all the sizes the same for the blanking plug as not finding any on the bay that lists them by thread.

Adrian

plenty off the shelf at my local PIPELINE center

Try these

http://www.airlink-compressors.co.uk/Fittings/plugs.htm#BLANKING%20PLUG%20M%20METRIC%20O%20STEEL