air in fuel line coming off filter

Howdy folks. I know there are a few references out there on where to start with this one, i.e. TDIFAQ, and elsewhere.

I am going thrru them and trying to understand more about this problem. Most references say that a few tiny bubbles is normal. These bubbles are pretty big if you ask me and they seem to come in waves. I think I have found one potential cause for air leaking into the system. My question is twofold.

1) The filter is new i.e. <3000 miles. Just performed the water separator maintenance, no water at all. When I bought the car the PO had an in-line filter set up that had no water separator. I immediately changed it out for the factory specified filter, but I was not sucking air until I went back to the original factory setup. Why is this? I am happy to change the filter out, if folks still think this could be the issue.

2) What fuel line material should I use between the tank feed and the filter and how long should this hose be? I think the black rubber line the PO's mechanic used is too short here as it does not even go past the barb on the black feed hose from the tank. It is about an inch or two short of the barb. Would this be a likely cause/location for a leak?

Thanks!
p.s. I think this could resolve my DTC 01268 issue as well

Mine has been putting air bubbles thru that line going on 10 years now! Seems to be no problems.........the issue has been discussed and discussed! I just don't worry about it!.........291k miles and going just fine!

On a serious note: I'm sure there is a reason and someone has written a Thread about how to find and fix. However, I have not seen it!

do you get any codes, i.e. quantity adjuster limits etc?

Mines had little bubbles through the same line too since I've had the car, totally normal and only a problem if the car is having fuel issues and the bubbles are big.

these are big bubble and I am getting 01268 Quantity Adjuster error

I used to get a lot of air into my fuel lines through the rubber itself. I bought new OEM lines and new clamps and it was good.

keendog said:

2) What fuel line material should I use between the tank feed and the filter and how long should this hose be? I think the black rubber line the PO's mechanic used is too short here as it does not even go past the barb on the black feed hose from the tank. It is about an inch or two short of the barb. Would this be a likely cause/location for a leak?

Click to expand...

I'm having trouble visualizing what you're talking about here.
Any chance you could post a photo?

CopaMundial, too dark tonight for a photo. I will try to get one in the day light. I am referring to the hose that connects the black plastic line running back to the tank and the top of the fuel filter. Mine has a black rubber hose connecting the two.

The black plastic hose coming from my tank has a bulb/barb about 2 inches down presumably to seal the connecting hose from air infiltration along with a clamp.

Super T, did you replace the lines from the tank to the filter? Where did you get these?

I think you might have an issue with the pump itself or something on the pump.

http://forums.tdiclub.com/showthread.php?p=949613

http://forums.tdiclub.com/showthread.php?t=102238

I thought that was the case too, but the pump was replaced in the last 6 months by the PO with a rebuilt pump.

I considered doing the hammer mod, but my Injection Quantity is spot on at 3.6-4 at idle. Believe me, I have been pouring over these threads to try and nail down the code and MIL issue. but, the fuel line issue is seemingly a simpler place to start.

Yeh probably is, hopefully it'll sort the issue out.