Help with fuel line questions.

[thetester]

Hey guys it's been a while since I have posted here but now I find myself needing a few questions answered. I am

new to diesel engines and have acquired a little bison 25. It has ran down quite a bit but still repairable. The lines

on top of the injectors are rotted and just done. They look like they are hydraulic lines with ferrules. Is it possible

to use regular line and hose clamps or are they way to pressurized for that?? There are metal lines going to the

bottom but rubber lines on the top leading back to the tank.

Question two. The owner left the flap up on the exhaust and water was pooled up in the manifold. I pulled the manifold and let the water drain. I've checked all the oil and no water mix. The motor still turns over freely as well. What damage could this have done and how to check. There are no glow plugs on this model. I am thinking the valves must index closed when the engine shuts down because I'm thinking there would be water in the oil.

Thanks guys if you can answer these questions.

 

[thetester]

This is the lines I am talking about.

 

[Soundguy]

I'm not familiar with a bison, however its common to have a high pressure line from the pump to the injector, and then to have leak off lines from each injector to the tank. The leak off lines may even be serial thru all injectors.

The pressure line must be fuel rated and for injection pressure.

Hose clamp and rubber linen won't cut it for the injector line, but can for leak off if it is fuel hose.

Many systems simply use fitted hard lines for the injector lines. If you can match the pump and injector end types, then brake line should work, bend your own.. etc

 

[truckdiagnostics]

I'm thinken those are return lines so low pressure, so yes regular fuel line and hose clamps should work. Isn't going to hurt anything to try it that way.

 

[thetester]

Thanks guys. Yeah the lines are in series meaning they connect from one injector to the other all the way to the tank. After you guys saying there are bleed off line, I think that's what these are.


Does anyone have an opinion about the water sitting in the exhaust manifold??

There is no water in oil and the engine does turn over.

 

[banjodunn]

The pressure line must be fuel rated and for injection pressure.
.

Many systems simply use fitted hard lines for the injector lines. If you can match the pump and injector end types, then brake line should work, bend your own.. etc

G'day as others have said normal fuel line and hose clamps will do for leak off pipes BUT not as Soundguy said brake pipe will NOT work for inj high pressure line also the ends are a special ball flare formed in a special tool , If you can scrounge an old high pressure line from somewhere and cut it you will see the heavy wall thickness used to stop the pipe swelling under injection pressure and not delivering the correct metered amount at the right timing.


Jon

 

[truckdiagnostics]

If water got into the cylinders there could be some rusting on the upper rings. They can rust and stick in the piston causing loose in compression and excessive blow by. This can make it hard to start and or excessive white smoke when running. We could debate for days on how to check and find out. You already cranked it over so here would be my suggestion. Make sure you have a working oil PSI gauge. Consider hand held manual gauge. Crank it over and run it, just make sure you get oil pressure right away. drain/change the fuel in the tank. if you change fuel filters you may have to deal with air in the fuel system. I would consider going after that, after I say if it ran. I use a hand held infared themometer watching either side of the water pump, thermo housing making sure it is coming up to temp even, don't want the water pump freezing up and it over heating. Good luck, no matter how you slice it there is always risk when you first start it. Even if you rebuilt it the risk is still there.:2cents:

 

[Soundguy]

G'day as others have said normal fuel line and hose clamps will do for leak off pipes BUT not as Soundguy said brake pipe will NOT work for inj high pressure line also the ends are a special ball flare formed in a special tool , If you can scrounge an old high pressure line from somewhere and cut it you will see the heavy wall thickness used to stop the pipe swelling under injection pressure and not delivering the correct metered amount at the right timing.


Jon

Done it, and it works. There is running proof in my pasture using brake line. Had a jap tractor with a bad line and had to make a field expedient repair. Not ideal, as I had to braze the ends on and that was a chore!


May bee the brake line they have down under is cheap?

 

[Soundguy]

PS this was like Bundy tube, .035. Not .028 copper nickle.

 

[Mace Canute]

Regarding brake line use for high pressure lines to the injectors, it all depends on what the operating pressures are. One size does not fit all...newer diesels run up to 43,500 psi. (Denso) but old ones run at a relatively low pressure, starting at under 2500 psi and going up from there. Knowing the operating pressure determines what line you use. They would have to be pretty high pressure though before brake line wasn't suitable. From Team Tube 3/16 inch seamless .035 wall thickness has roughly a 16755 psi bursting pressure, 1/4 inch is 12600 psi and 5/16 inch is 10063 psi. Surprisingly high burst pressures for such thin wall tubing, eh?

If anyone wants to have a look at fuel injection systems, here's a site with quite a bit of general information. http://www.disa.it/pdf/03HystoryOfDieselFuelInj.pdf