[gbgreen59]

Hi All, I have a Volvo MD11D 25 HP engine in my boat. I pulled the rubber fuel line that goes from the engine to the metal fuel line that goes to the tank. There was a leak at the fitting on the engine side. I've not replaced fuel line before and I am wondering what is needed to ensure there are no leaks at the fittings. Is any type of sealer used on threads and/or pressure fittings? I didn't see any sealer on the threads on one end. I only saw washers on the end with pressure fittings.

BTW: The boat is vintage 1984.

Thanks in advance for the help.

 

[overbored]

depends on the type of fitting. if pipe thread then use a fuel resistant thread sealer. if they are a flare seat type fitting or sealing washers then no sealer. if there are sealing washers they should be replaced. if you use any kind of sealer make sure it is put on the threads at least on thread back from the end of the male thread. you do not want to get the sealer into the line as it may cause a clog.

 

[celenoglu]

Replace the metal tubing going to the tank and the rubber tubing with a single rubber tubing.

 

[gbgreen59]

@overboard. There are pipe threads on one end and washers on the other. I'll proceed as you've described. I'll replace the washers and ensure the end of the threads does not have sealer on them. Thanks.

@celenoglu. Oh, I've already got the boat yard parts department making up a new rubber tube, which will connect to the existing metal tube. What issues are there with keeping the existing metal tubing? For something that old, is the concern that the metal tubing may be corroded and then fail in the future?

 

[celenoglu]

1. Each fitting means a possibility to leak.
2. It is always recommended to use rubber tubing instead of metal tubing. Vibrations cause cracks on the metal tubing.

 

[MarkSF]

I've never heard of fuel line sealed on pipe threads. What on earth do you mean? Have you considered taking some pictures, as otherwise any advice is complete guesswork.

 

[gbgreen59]

I've never heard of fuel line sealed on pipe threads. What on earth do you mean? Have you considered taking some pictures, as otherwise any advice is complete guesswork.

The reading online that I was doing said that the threads on fuel line is NPT. I probably should not have used the term "pipe". The information I found is consistent with what Overboard was saying.