Fuel filler neck inner coating

I have been wondering about the identity of the dull red coating on the entire inner surface of the fuel filler neck hose from an '87 Porsche 944.

anyone know what the coating is or could be?

There’s also a cloth-like outside material on the outside I presume is to prevent chafing.

I can get a rubber hose close to the specs from Fuel Filler Neck Supply on the internet, but I don’t understand the coating/cloth. Oddly, NAPA and AZ are not doing the job for me. I also. Posted on a Porsche site a while ago and got no suggestions.

EDIT: forgot to say that the hose is no longer available from Porsche - perhaps that was evident? A credit to the readers of this thread in any case.

UPDATE : was poking around car talk today, figured I’d update this: the only workable option on the internet that I have found is http://www.fillernecksupply.com/ … I have had to get some test cuts of tubing from them to get a good ID/OD match with the additional inner seals, but the service was very good - I could call and they were helpful, and the shipping was quite good too. The cuts I got are plain rubber - no coatings. looks like I’ll have

The only thing that I can think of is Red Oxide Zinc Chromate Primer. It’s tough stuff and nothing I know of will dissolve it after it’s dried. It’s a dull red when it dries.

Neither NAPA nor AZ would be expected to know anything about a Porsche filler neck hose or the coating, I’d think, that’s a factory part. And it’s rubber? That could be molded in red rubber.

NAPA and O’Reilly have often stocled generic fuel filler hose. When a straight section of hose is required one or both those suppliers have had what was needed. But as for the lining, all the fuel lines I recall were rubber inside and out. There is a clothlike material within the layers of rubber on most automotive fuel hoses and either ethanol or friction might have delaminated the inner rubber lining.

@JuniorMint - Is this what your tank/filler setup looks like? If it is, are you talking about the rubber hose, or the metal part?

@texases Yes, the thickest black section between the tank and the aluminum part… did you find that on eBay?

Thanks for the suggestion of red oxide, red rubber… The website I found useful is http://www.fillernecksupply.com/servlet/StoreFront

As for NAPA, I think locality matters, for AZ less so. I saw a pic of a couple things from NAPA, but no help even on the phone - almost like the guy wasn’t interested in selling one.

The counter help at parts stores is declining, @juniormint. Even when you are facing them across the counter a great many won’t or can’t look up the proper hose when there is no specific part number. My local NAPA store has 2 long time employees who know the correct hose for fuel and only need the diameter and length. O’Reilly also stocks several sizes here but I make myself at home, go behind the counter and match up and cut what I want. Auto Zone and Advance have never stocked such hoses.

Filler Neck Supply Company sells replacement filler hose by the foot. Simply measure for the diameter you need, and you can order it from them by diameter.

The coating isn’t important, as long as the hose is properly rated for gasoline. I recommend a visit to their website.

Bump to show edit of original post.

Shouldn’t edits of the starting question be made to bump it to the top? Is @cdaquila the user-moderator to ask?

Any filler hose of the proper dimensions will work fine, as others have said. Why are you concerned?

@texases not why, but what - the coating and also the cloth-like surface. I don’t know what they do or what they are there for. I might get hose that is smaller by a mm to account for the hose being on the tank for 25 years… Also it is a big job to do this, I want the best plan possible before reassembly.

BUT I am gathering that —>>> if hose is rated for the fuel being used, it should be good to go<<<— - though as might be noticed in other postings, I can’t help but go to great lengths to understand something.

I understand. I wouldn’t be concerned with a high quality replacement that looks a bit different.

As for dimensions, measure the metal part outside diameter and the old hose inside diameter, then call the website you found, they should know what to use.