Does anyone make a new one or have a good old one, or even a suitable replacement?

You might have to search the threads here for posts about parts and parts suppliers and see if they're still going or look for a suitable alternative.

I assume (so could be wrong) want what I'd call an expansion tank but if you mean anything to do with the actual radiator there are those that can service and repair them (or there used to be just a few years back).

Good luck.

On 19/02/2026 at 13:10, nta16 said:

I assume (so could be wrong) want what I'd call an expansion tank

Yeah, it's the header/expansion tank, radiators are easy as they can still be obtained for not too much money, I've bought a new cap which for the moment appears to have resolved the problem, but we'll see when I eventually get it on the road.

Glad it appears to be sorted.

If the expansion tank is plastic and cap is plastic (I forget the colour, yellow/ blue? screw on then they needed replacing back in the day when many might think it was head gasket failure and all that was needed was a new cap. With the quality of modern replacement parts I would possibly get a spare replacement too or if there's a rubber seal involved just get a suitable er, rubber seal too or instead.

What is a Bugrat BTW, a kitcar or custom/mod or other special? I'm thinking like VW Dune bug sort of thing or ratrod. There used to be a place round here that made Poker speedster replicas based on Estelle's IIRC.

It's a plastic tank with a metal pressure cap.

As to Bugrat you're on the right lines(is) with a dune buggy, this is what it looked like in 2007 when I last owned it

9 hours ago, Bugrat said:

It's a plastic tank with a metal pressure cap.

Your 'Author's stats' show you having a 1990 Bugrat so I wrongly thought it was made from a 80s/90s Estelle 2 Rapid and they had a plastic cap.

Modern made metal pressure caps aren't as long lasting as they used to be so need changing and more often, the choice is trying to get a decent old make one or whatever you can get and change it every x-years before it plays up or goes wrong. IIRC(?) the last good one I got was a Motorad one, made in USA(?).

12 hours ago, nta16 said:

Your 'Author's stats' show you having a 1990 Bugrat so I wrongly thought it was made from a 80s/90s Estelle 2 Rapid and they had a plastic cap.

Ah, well. maybe it's not the original then, Sorry I don't know. It was built from a 1989 136 Rapid I was lead to believe, I also understood it was a one donor car, so I presumed that header header/expansion tank came from the original car. I will get an image later today

Don't go by my poor memory and my last Škoda was a 1987 130 Rapid Estelle 2 saloon so I may have remembered wrong or things were changed later.

I went on my ex-neighbour's car website to see if I could see your model but I didn't have the manufacturer's name. IIRC there was a Porsche Speedster replica kit made or going round Northampton decades back based on the Estelle 2, again I've no idea of the manufacturer's name.

For the metal pressure cap it does off course have to be the correct pressure rating, I would guess at something like 15 lbs but could well be wrong.

If you have Porsche or Golf GTI owning mates I hope you've seen the following from back in the day. 😄

Edited 23 February23 Feb by nta16
Rapid (1986) was model before last