Tank compression fitting ferrule vs viton

(Douglas) #1

When I took my fuel tank compression fittings apart for the return line and the sump tank breather I found (leaky) brass compression fittings.

I ordered what I thought were the right replacements from SNG (and they finally arrived after a solid month of backorder) for those two fittings/lines. What came is in this photo. The short two ended piece (for the return line) has the brass compression fitting (with ferrule) I expected for the connection to the bulkhead but on the other side is a green viton piece and barb like ridge behind it. This different type is also on the tank end of the breather hose.

Question: can these two types of fitting be used interchangeably or not? Last thing I want is to install new pieces and put it all back together just for it to leak again but at the same time these were the parts I could find (and they said they fit my 89 and the new reproduction tank I bought from SNG as well). What’s the theory behind the vitons and the ridge/barb behind them?

Are the brass and viton different styles but interchangeable?


(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #2

We can only hope that Jaguar finally recognized the problem and issued a fix!

Are you sure the Viton thing you’re looking at isn’t just a protective cover for the fitting that you’re supposed to remove before installing?

Are the threads correct? In the pic, the threads on the Viton end look a bit coarse.

I dunno how you’d tighten the B nut securely on Viton. I’d be worried about damaging it. And when done, I’d expect the fitting to feel a bit loose and wobbly. Perhaps a good thing, as long as it doesn’t leak.

I also wonder if these are intended to be installed dry, or whether you should apply either a lubricant or a sealant when installing. The fact that the B nut doesn’t appear to be brass is another concern. I presume the fitting it threads into on the tank is brass? If so, OK. If not, it’d probably be a good idea to apply some anti-seize compound to the threads on that B nut but not inside the female fitting so you don’t push any anti-seize into the area the viton is trying to seal.

Finally, there is some chance you got the wrong parts, and these hoses are intended to fit a later model. I think the much-later model may have done away with threaded connections altogether and just welded barbs into the tank, but perhaps there was a version in between that was still threaded but used Viton instead of the brass compression fittings.

Sorry I can’t be more help. Perhaps someone knows more about these things. I seriously doubt they are a Jaguar invention; it’s far more likely there’s info out there somewhere about an upgrade to brass compression fittings.

(Greg) #3

I also ordered a tank and both fuel lines from SNG for my 88 XJS. Mine came only with brass fittings, no green fittings. They fit no problem with no leaks.
Parts CBC8189SS and
CBC6346SS. (the SS are their stainless steel versions)

(baxtor) #4

Have you tried removing the green items? As Kirbert said you may find they are protection for the O ring (it’s been a while and may be mixing this and air con fitting) normally fitted on similar fittings.

(Greg) #5

A few extra things I did if you’re interested -

  • I painted a coat of Por15 on the bottom of the tank. Figured why not?
  • Put a dab of anti-seize on the BACKSIDE of the brass fittings (where back of ferrule touches the connection nut), this will make it easy to take apart down the road, just in case.
  • Poured a gallon of gas through new tank just to make sure it was clean.
  • Attach the fuel filler parts AFTER you’ve put in the rubber washer that came with the tank into the tank fill spout (Yeah, I forgot, so had to do the fuel filler twice)
  • Removed trunk lid.
  • disconnected fuel line at first FPR, sprayed carb cleaner into line at trunk end, blew through until came out clean.

I hope everything goes well for you like it did for me. Only issue I had, was trying to put the tank in at an angle. After 20 minutes of swearing, I found It ONLY goes in straight.

(Douglas) #6

Hmm I suppose it could be protective but even if it is it’s definitely not the right part. Further examination shows that you are right on all counts: the threads are different and won’t screw into the fittings in the tank even if they could fit there which they can’t because of the barb I mentioned before.

Greg helpfully listed the parts he purchased in this thread–I thought I bought the same ones but lo and behold I just went back to my purchase email and I guess I messed up because what it says I ordered isn’t what I thought I ordered. Sigh…

Thanks very much for your help and thoughts! Looks like my best bet at this point is to either reuse my old fitting nuts (with new ferrules). The nuts are in fine shape–I was buying new components to be safe. What I will probably do is reassemble with the old parts and possibly invest in the right ones (that Greg got) in a little while and swap them in.

It’s been amazing how fast the fuel smell went away. I washed all my trunk carpet pieces and the whole trunk with warm/hot water. The wool shrunk a little but stretched out nicely again with no damage and best of all none of it smells like gas at all! I am really close to getting Redcat running again after about 2 months of all of this so I can’t wait for what will hopefully be my first gas smell free drive.

(Douglas) #7

I thought I ordered these but turns out I got something else–clearly my mistake not SNG. Oh well!

(Douglas) #8

Very helpful–thanks!

I almost certainly would have forgotten that rubber washer–I have it but actually recalling to put it in is another story.

I got the tank in last night–you aren’t kidding!! There isn’t even a 1/4in of play room to guide it in. I ended up sitting on the floor of the trunk with the tank if my lap. Only angle where I could only support the tank’s weight and keep it straight at once. It is in nicely though and my new mat (homebrew out of neoprene) and new foam keeps it perfectly snug in place. For future readers, 3/8in neoprene was perfect under the tank to maximize padding but still allow the tank in without jamming at the top.

(Douglas) #9

Yeah they come off easily enough but still I’m quite clear I bought the wrong parts. Thanks for the thought!

(baxtor) #10

Did you remove the infamous pop rivet beneath tank?

(Douglas) #11

I cut it down with a hack saw–I left maybe an 1/8in showing above the surface. I’m not sure what it holds in place but I was nervous to just remove it entirely.

I then made a little pancake of steel stick and put it over the small remaining nub of the rivet. Molded that down and let it cure before repainting. It is hardly noticeable after the paint when over it and I am confident it will hang on to what is left of the rivet and fully protect the new tank I put in–especially because of the cushion of neoprene that the tank sits on.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #12

I wanna know what parts you bought!!! Is there some version of Jaguar those hoses would fit?

(Greg) #13

looking at your photo, you ordered 8639 for the return line. That is for VIN 161714 and up. Before that VIN is 8189, which is the one I got and I assume you should get.

SNG Barratt’s website is a bit confusing, you click on the correct year and click on fuel systems, and I see the 8639 pops up in the list. BUT you must click on the correct assembly picture above for your engine (5.3 liter), and then navigate on the right for fuel return hose, and then click on the correct VIN.

(Dan Solomon) #14


strong textContinuing the discussion from Tank compression fitting ferrule vs viton:
(upload://4aN8QI6HflsiGIFhDbykTLhlJW8.jpeg) On my 92 5.3 The Viton seal is used on my car for the inlet to the fuel rail and also the fuel pressure regulator. I cannot believe that you have them! I have looked all over the world for those two viton green seals no one has a clue what I’m talking about! At the moment I have shoved o rings over the end of the nipples for a seal .If you can’t make them work let me know and I will buy them from you!

(Douglas) #15

No idea if they would fit but maybe this is a facelift thing…

Here’s a screen shot from the email receipt.whatibought

(Douglas) #16

Yeah you’re right! I got 8639 and 8637. Not sure how I messed that up but alas I did… 8189 is what I wanted and I will probably be ordered it soon.

(Douglas) #17


Sure, I will let you know. I’m probably going to use parts of the parts I bought in a creative way but I seriously doubt that the vitons themselves will serve me any purpose. I can’t see any place where I would put them on my '89 in which case I’d be happy to move them along!

Just out of curiosity would you send a pic of where they go on your facelift car?

(Dan Solomon) #18

I’m new to the form having some problems trying to do this over my telephone at the moment. Hope the picture comes through.

(Dan Solomon) #19


One connects to the Inlet on the fuel rail driver side. The other goes into the fuel pressure regulator on the passenger side of a 92XJS

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #20

Is that one of the Viton seals with an O-ring added? Some type of bodge?