Duratec radiator top hose question.

[Nigel B]

I found myself wondering recently why the radiator top hose on my 420R is a traditional rubber item, when all the other coolant hoses are silicone.

Is there a specific reason Caterham fitted a rubber top hose? It’s long & quite a convoluted shape, so I was wondering if that would mean it would be difficult to make in silicone? Or is there another reason? Every other Duratec car I’ve seen is the same.

I was contemplating getting a replacement made in silicone, but I can't help but feel there may be a reason for the original rubber construction that I'm missing. Or perhaps I’m over thinking it?

Does anyone have any thoughts?

[ScottR400D]

The Duratec top hose is a custom made item, which presumably was less expensive for CC than a silicone version, Nigel. 

From memory the main bottom hose is similarly made but most, if not all, of the other hoses are just cobbled together from readily available silicon items. 

I forget what year your car is Nigel but if you're lucky you have the radiator system that the hose was designed to fit. In recent years they 'upgraded' a system that didn't need upgrading but they failed to redesign that hose with the subsequent issue many owners have had. It just doesn't fit the recent cars system. 
 

[MTW]

I have bought a 620r silicon radiator hose that I'm planning on using, I saw CtrMint has done this already so I'm going to give it a try too when I change to a new radiator. You have to cut the current rubber hose and add the silicone hose which runs front the end of the inlet manifold to the radiator.

[Jonathan Kay]

Whatever it's made of I would want to be sure that it isn't applying any load on the radiator, except for the circumferential sealing on the stub.

And I'd take the opportunity to check how the radiator sits on the mounting brackets for the same reason.

Jonathan

PS: There are three commonly-used suppliers of silicone hoses and they all seem to have happy customers. There are sometimes Club discounts.

[Nigel B]

Thanks for the replies everyone, interesting!

My car is from 2017 Peter, so thankfully I have the earlier radiator, with the separate Mocal oil cooler. I was aware of the problems people have been having with leaking radiators, but thankfully it's not a problem I've had. I'd imagine lighter, silicone hoses would help from that point of view, putting a little less weight on the radiator.

I wasn't aware of the modification using a 620 hose, I'll have a look at CtrMint's blog. Although I think I'd prefer a hose that's made entirely from silicone, if at all possible.

I had a set of silicone hoses made up for my last Caterham by a company called Classic Silicone. They did a great job of replicating the original rubber hoses, so I'll probably contact them again.
 

The coolant needs changing & I've had a slight, intermittent leak from the hoses at the rear of the engine for a while. I suspect it's just a hose clip loosening off, but it will need a closer look. It seems like a good opportunity to replace the rubber hoses with silicone while I have the system drained.

Thanks again!