Anyone know the inner diameter of the rubber hose that attaches to the heater pipes in the bulkhead?

One of mine is cut in half to attach to the LPG system and I have a slow drip/leak from it. It looks a little old and crusty so I'll replace it.

I don't want to pay for the proper part just to cut it in half so I'm looking to get some silicone coolant hose for it.

I don't know the ID of the existing hose and trying to avoid going out in the cold to pull it off, measure it, refit it and bleed the coolant system again - only to have to take it apart and bleed again when the new pipe arrives.

Anyone know the ID?

They're an odd size - I think the ID is about 21-22mm at the firewall end. The original hose was about £18 each last time I bought some!

Ah, so does that mean they're a different size at each end of the hose?

I guess I will need to go and measure it myself then - the diameter in the middle could different to the measurement at the firewall end.

I've just bought a couple of Britpart ones and they are 20.5mm id at the bulkhead end

At the T they are 28.6 od and the wall thickness is 4.4mm so probably about the same.