Fiber Gaskets and Braided Fuel Line

I am throwing in the towel on fiber gaskets on the carbs. Leaking on my Dino and now on my Stratos. They were installed correctly and tight. Over time with fuel and heat they lose their sealing ability. Strictly copper or aluminum from now on. Second time I have found the cloth covered fuel line leaking as well and they were just a little over a year old. I was trying to search for a premium grade cloth braided fuel line but I think none exists. BMW, Porsche, and VW forums all contain similar rants about the cloth covered fuel line splitting. Some PTFE fuel lines have a similar cloth-like cover but they are AN sized and use AN fittings and don't work with regular hose clamps. All of the above is just too much of a fire hazard. Using Gates Barricade hose for now.

 

I have not used cloth covered fuel hose for many years for the same reason as you mention. It is a real shame though since it makes a big optical difference.
Best

Peter

 

a nylon braid is available to R9 specification, slight sheen to it but looks better than just plain rubber

https://www.anhosefittings.com/lightweight-nylon-braided-viton-sae-j30-r9-hose-for-fuel-and-oil.html

or have you thought of using the overbraid . There is a heat shrink product around and works well on a good quality R9 spec hose

https://www.carbuildersolutions.com/uk/black-nylon-cable-overbraid-13mm-per-metre

and finish off with rubber end caps

https://www.carbuildersolutions.com/uk/rubber-hose-end-caps-braided-12mm-id

Tony

PS - check the OD of the fuel hose matches the overbraid and end caps.

 

I've looked at the braided viton and PTFE fuel lines but the AN sizes are too big and regular hose clamps are not supposed to be used. I may get some of the PTFE line to play with. That would be the best because it is supposed to be good for a long, long time.

 

Thanks for the links Tony. I might try to get some of the nylon overbraid and lock it with heatshrink just to see how it looks on my boxer project.

 

You did your research and found out the truth. That old spec rubber just doesn't work with the modern fuel chemistry.

 

The cotton covered hose is not suitable for Ethanol based petrol, it dissolves the rubber and can perish in as little as 6 months. There is a lot of it on the market and is only to R3 spec.

You need the hose covered under R9 specification (Codan SAE J30 R9) as its suitable for higher content ethanol fuel and fuel injection systems, its perfectly OK for low pressure fuel systems but not vice versa. Select the hose which is about 10% smaller than the fitting, not equal too it, that way you don't crush the hose to make a seal.

I have used the overbraid on my car for some time and its perfect but as I said before it has a slight gloss to the material. I used the heat shrink product which helps keep the overbraid tightly fixed to the hose.

To finish of the ends use the rubber end caps and petrol clips / clamps (not jubilee) - the finish looks professional.

Tony