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MG MGA - Expansion tank

Im thinking of fitting an expansion tank to my A, has anyone any advise on what to use, have you done it, have you any photos, any input would be most welcome, thanks, Vin.
Vin Rafter

Steve Gyles is the man
dominic clancy

You might want to check Barney's solution at
JM Morris


As said above, Barney covers the description very well of an unpressurised overflow system at:

My system is a pressurised expansion tank, as copied from the MGB, and common in many modern cars:

Steve Gyles

Like Steve I fitted the MGB system and it works well. However in using the MGB copper tank with black pipes you never get to see how the coolant is behaving and I sometimes think it would be nice to have a vision tube somewhere.
J H Cole

I think Steve must have copied mine :)

Mine is Exactly the same as Steves and the key is the cap for the existing radiator top.

I used the midget expansion tank which must be the same as the MGB.
Robert (Bob) Midget Turbo

Attach a photo of solution I used. Following advice on a non pressurised system on Barneys site I used a windscreen washer bottle and made a small bracket to fit it to the top radiator mounting bolt. Two clear plastic tubes short one from the radiator overflow and one bottle vent/overflow down to mother earth via the existing guides. Quick to install and quick to remove if necessary and has been working for about 8 months without hitch....and you can see it working .
Two holes in bottle for radiator tube which goes to the bottom of the bottle and one for the vent/overflow tube which starts just under bottle cap. The hoses are a push fit through the cap and therefore make a good seal.
You do need a radiator cap with two rubber seals so the water is sucked back in when the radiator cools...and this is easy to get.

Neil Ferguson

"You do need a radiator cap with two rubber seals so the water is sucked back in when the radiator cools...and this is easy to get."

All modern radiator caps have a double seal and a check valve that enables the expelled coolant to be pulled back into the radiator as the system cools. See the article, Expansion Tanks, Coolant Recovery System and How the Cooling System works in the Other Tech Articles section of my web site at: Cheers - Dave
David DuBois

We have a basic square bottle located in the front corner of the radiator, with a tube connected to the radiator neck. We did have to get a recovery neck installed onto the radiator and then used a recovery radiator cap. The overflow is not pressurized but the water is returned into the system once the water cools down.
Seems to work fine and keeps that extra 300-600mls available.
DJ Lake

This thread was discussed between 06/06/2010 and 07/06/2010

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