Bukh DV 20...Maui...high pressure Fuel lines

[unclebraddah]

So I have finally found the problem. Harvey and MarkJohnson are the big winners. It seems it is where the fuel line connects to the injector with a cap nut...inside this nut is a bearing of sorts that stops the nut from screwing down farther on the injector. It catches on the mushroom base of the line tip. well this bearing(washer) is split so when I am tightening the nut on top the injector this bearing(split) is spreading allowing the nut to screw down farther than it should, never really tightening on the injector and allowing air and pressure release into the seating area. So I guess I need a new fuel line. Could I cut the line, put a washer up in the cap nut and solder the line back together. The washer/bearing needs to be smaller than the mushroom tip and fit in the cap. I would rather replace the line but it is $200USD with shipping. Any ideas as to how to make it cheaper. This the line from the pump to the injector. Duplicate it perhaps. hard to find.... /forums/images/graemlins/confused.gif

 

[Peterduck]

I really think that you need to take this one to an injection expert. I certainly don't believe that you could successfully rejoin an injection line with solder, the pressures are just too high. Silver-solder, maybe. Those high pressures are going to make sealing the whole thing again very difficult. I think that an ordinary washer in the works is going to give you sealing headaches that you don't really need.
Peter.

 

[oldharry]

I am inclined to agree with Peterduck. High pressure lines just have to be right - no compromise, otherwise they fracture, leak, or deliver the wrong pressure and upset the timing injection timing.

Maybe not so important on a basic engine like the Bukh, but the length and bore of a diesel injection pipe are carefully calculated to ensure the pressure builds to exactly the point to open the injector at the right moment. The injection pump needs to be pushing against exactly the right amount of diesel in the line to acheive this, so shortening the pipe may adversly affect the engine performance - probably not noticeably so on a Bukh, but even so!

 

[unclebraddah]

I hear ya guys. Im discussing it with a tube maker. I just wish someone would show up and say.."Oh I have an old one of those lying around I can sell ya...