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Miker · Joined: 25 Jan 2005 Posts: 47 Location: Cali

ok so, I have a 1980 931. I have pulled the fuel system apart. I am now putting it back together but, when i look closely I noticed that....
1. is the injector supposed to have a metal o-ring at the bottom where it hits the head, or just the plastic?
2. the flange nuts (the fuel line nuts with hole) should have a metal o-ring on both sides I know this, but I seem to have two sizes in my pile, one style i copper and thin, the other looks like steel and slighty thicker? which one goes first? or do I have the wrong ones?
3.Lastly, I also noticed that the head size of the flange bolts are alos diff sizes. Are the larger specific to certain lines? or?

thanks,
Mike

Smoothie · Posted: Sat Apr 16, 2005 11:51 am Post subject:

1. As far as I can tell, there should be a metal "sealing ring" there. The parts list usually lists rubber o-rings as "o-ring" and metal rings as "sealing ring" - and they're calling the 931's injector rings "sealing ring" in A10x13.5 size.

2. All of mine have aluminum sealing rings on both sides, but I'd imagine copper does well too. Obviously nothing like putting it together, pressurizing, and checking that it doesn't leak, but I believe that all aluminum sealing rings of the same thickness were used originally.

3. Sure - the fuel supply and return lines use larger banjo bolts or "hollow bolts" as the parts list calls them. I don't know off hand what size they are (either M10 or M12 I'd guess), but the smaller ones are M8.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

Smoothie's got it covered... when I bought new sealing rings from the dealership, all the various sizes were copper. If you need to order some, you should go and get a handful of extras while you are at it. These things have a tendency to get lost.

One last piece of trivia to note is that when you put the lines back on the control pressure regulator (AKA WUR), note that there are two different sizes of banjo bolts on the device. And, you need to attach the top line first, otherwise with the bottom one in place, you can't get a wrench on the top one.
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'79 Eurospec 931