Air leak in fuel line - how to find it? - PeachParts Mercedes-Benz Forum

Blevinsax · #1 04-08-2007, 03:21 AM

I have an air leak in my fuel lines - particularly on the WVO side, but I have not been able to fix it because I do not know how to find it.
What is the best way to locate an air leak in fuel lines?

Magoo · #2 04-08-2007, 11:14 AM

Really difficult to diagnose without clear fuel lines...
You probably already tried tightening clamps but it almost has to be a connection problem. My brother had air issues with his setup and found he had to install clamps on all the fittings. Sounds dumb, I know but they were very tight fitting connections and so he thought he might get away with it. As the filter slowly clogged, the connections started sucking air.

Blevinsax · #3 04-08-2007, 02:04 PM

I have tightened every clamp I can get to, but it still sucks air. I don't have too much of a problem in regular driving, although I do suspect my rough idle after a bit of driving is air-related. The main problem is when I stop the car and leave it for a little while. That's when it develops an air bubble big enough to stop to motor. Perhaps it has small bubbles throughout the line, then they all converge in one place when the fuel stops flowing creating a big bubble.

Is it possible that my lift pump could be leaking? I've included two photos of my lift pump. It is wet under the lift pump - I touched it and it does not smell like anything - no smell. I was hoping I would be able to smell diesel or WVO, but it has no smell. Does it look like it might be leaking in the photos? If so, is there a seal under the lift pump that might be bad?

I don't know abut clear lines since I'm running a really hot WVO setup. I don't know how clear lnes would withstand the temperatures. Is there a high temperature clear fuel line out there that would work?