O-Ring on Turbo Oil Feed Line?

Stromaluski

Veteran Member
Joined
Oct 23, 2013
Location
Greenville, SC
TDI
'67 Deluxe Bus, '80 Rabbit Truck, '92 Corrado, '10 Cup Edition
I've been collecting parts to upgrade the turbo on my AHU to a VNT-17 and ended up with a question about the feed line. I purchased an aftermarket, braided feed line and realized that the end of it has an o-ring in a groove that was cut into the fitting. This seems out of place to me... I would think the fitting should seal without the o-ring, as it is the same idea as the flare on brake lines or AN fittings, for example. The aftermarket ones I find online all seem to have this o-ring; but as far as I can tell, the OEM feed lines do not. To be fair, though, I have no first hand experience taking off the feed line from an ALH. All my experience has been on a 1.8T which uses a banjo bolt and I am simply going off of second hand knowledge and diagrams. I don't see a seal shown in the part diagram.





So my questions are whether that o-ring should be there or not? If it should, is it the right size? And if so, how do I get it into the union on the turbo without slicing through the o-ring?
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Looks out of place. My gt2052 on my AHU is the same fitting as all other turbos, a 1/4" NPT threads. Put that to -6an or -4an, can’t remember right now and just got a braided hose and modified the banjo on the oil output I got a banjo -4an (if that was the size, can’t remember) and used the stock banjo bolt. But I did port the banjo to allow more flow in the inside so it was more similar to the stock. I have never seen an o'ring on a turbo ever. That fitting gets HOT and I mean HOT. I would think that o'ring would fail very easily.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Also i doubt that nut will even fit btween the compressor housings..... looks like the nuts interfere
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
I have one of those o-ring oil lines as well, and the fitting mine goes into has a larger I.D. than the one you have. I have thousands of miles on mine and have had no oil issues with it, in spite of the fact it has been removed and re-attached 5 or 6 times.
 

1854sailor

Resident Curmudgeon
Joined
Aug 10, 2004
Location
Westerly, RI
TDI
2015 Golf SE SportWagen, 2015 Golf SE Hatch Back.
Looks like the wrong fitting altogether. This is the only type of compression fitting that I've ever seen on a VW TDI turbo...
 
Last edited:

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
the taper should seal on its own, but w/e
there's a groove in it for an o-ring, so leave the o-ring in there

if it doesn't clear the bolt holding the compressor housing on, you can toss that bolt, as there are 5 more holding it on. Or you know, clock the housing a little to put it away from the oil fitting. Whichever is easier.
 

ketchupshirt88

Veteran Member
Joined
Oct 31, 2012
Location
waupaca, WI
TDI
2005 Passat daily, a bunch of others in the graveyard out back...
ive used ebay flexible feed lines with that o-ring in there on 3 different TDI's now without any issue.

2 of them are still fairly fresh installs but one has over 3 years on it now without noticing a leak.
 

Stromaluski

Veteran Member
Joined
Oct 23, 2013
Location
Greenville, SC
TDI
'67 Deluxe Bus, '80 Rabbit Truck, '92 Corrado, '10 Cup Edition
Where did you get it?
Amazon. https://smile.amazon.com/Turbo-Jett...1514208058&sr=8-1&keywords=tdi+turbo+oil+line

Also i doubt that nut will even fit between the compressor housings..... looks like the nuts interfere
The picture is deceiving. It fits ok between them. I didn't think to make sure that I could get a wrench on it, though. I'll have to check that.

I have one of those o-ring oil lines as well, and the fitting mine goes into has a larger I.D. than the one you have. I have thousands of miles on mine and have had no oil issues with it, in spite of the fact it has been removed and re-attached 5 or 6 times.
the taper should seal on its own, but w/e
there's a groove in it for an o-ring, so leave the o-ring in there
ive used ebay flexible feed lines with that o-ring in there on 3 different TDI's now without any issue.

2 of them are still fairly fresh installs but one has over 3 years on it now without noticing a leak.
Glad to hear that there have been no issues using them. I would have thought that the turbo would get way too hot for the o-ring and it would end up melted?
 

[486]

Top Post Dawg
Joined
Mar 1, 2014
Location
MN
TDI
02 golf ALH
and that there's another o-ring between the compressor cover backing plate and the center housing
much closer to the heat
 

Stromaluski

Veteran Member
Joined
Oct 23, 2013
Location
Greenville, SC
TDI
'67 Deluxe Bus, '80 Rabbit Truck, '92 Corrado, '10 Cup Edition
The fitting appears correct, but the o-ring cross section is too large. The fitting style is DKOL, it should have the same dimensions as the stock compression DKL ("olive" style) fitting but the hose crimp fittings in this series have an o-ring added to make up for the lack of conformability of the formed one-piece fitting.

It may seal without the o-ring but for insurance, I would find a smaller cross section o-ring and go with that.
Sounds like a good plan to me. Thanks! :)
 
Top