Coolant expansion tank

[Ulf]

Yes, it's me again...
While the FI-pump ordeal seems to be nearing its end (new pump arrived and has been fitted and awaiting fine tuning) , at new issue has raised its ugly head - a leaking coolant expansion tank (early flat type made from brass). There is a really nice refurbished one for sale at EUR 998,- (1.166 USD), but this seems somewhat excessive - especially in the light of my recent expenses.
So what are my options? Solder it temporary and have a radiator specialist weld it properly later? Fit a later and more readily available tank - are they even interchangeable in terms of brackets and pipes? Or just bite the bullet and order the refurbished tank?
It's not a huge leak, so how dangerous is it if I keep an eye on the temperature? (having owned several Triumphs and MG's I do that anyway).

Your opinions are, as always, greatly appreciated :-)

Ulf

[mdsalemi]

Ulf, I don't know the market where you are, but my later style coolant expansion tank was also an issue. Here's the story.

Being brass, and NOT one piece, they are indeed soldered--not brazed or welded. Most solder is a low-melting temperature.

I wanted to powder coat my tank as some of the paint had blistered off. Some here said they had that done without issue, but other said no. My friendly local powder coater would first have to remove the paint and then pre-treat and pre-heat the unit anyway, so he offered to do this at no charge (I had other items in for powder coating)

During the bake, the solder flowed out of the joints and moreover, revealed metal perforations. Clearly it would not withstand their powder coat bake process.

I took the overflow tank to a radiator shop (of which we have plenty here in the USA) and they tested it. They soldered all the trouble areas, and pressure tested the tank and all was well. I took it to my body shop and they painted it.

Do it once and do it right.

[Pawel66]

Having no idea about neither technicalities nor practicalities of the early fuel expansion tank, I would not pay $1000 for refurbished one, but I would refurbish it myself (i like doing it) or have some specialist refurbish it for me. It does not sound like a difficult job.

And yes - do it once and do it good.

Satisfaction guaranteed.

I would save money for items more difficult to refurbish, just to give you examples of $1000 vicinity: throttle switch, cold start valve - shall I continue?

[RPSchuetz]

I’m wondering - does the radiator / cooling system have to be completely drained before removing the expansion tank? I need to address a small leak on mine...

[teahead]

Draining?  Shouldn't be required.

Ya, I think radiator shops would charge $50-100 USD to fix any expansion tank leaks.

Well worth it than buying ANOTHER unknown used one.

[Tyler S]

You would need to drop/drain the level of the coolant in the system below the lower pipe on the expansion tank/reservoir.