Yanmar 3GMF: Torque spec for fuel lines at Injection pump

[hunter34austin]

I'm having a fuel leak on the injection pump and I think it's the high pressure fuel lines (I see diesel on top of the pump after running the engine). Before digging deeper I wanted to tighten the fuel lines at the pump. Does anyone know the torque specs? Can't find them in the workshop manual.
Also the access is very restricted - Is there a chance to get a torque wrench in there with all three lines in place or do I have do remove all lines first and then install them one by one?

 

[Benny17441]

Do not know of torque specs for fuel lines, You have to make a call of what is adequately tight without overtightening and then inspect for leaks. Do not try to eliminate a persistent leak by continuing to tighten. As a general rule if high pressure fuel lines are tinkered with or removed they should be replaced with new ones. Identify the culprit line and see if by tightening a little at a time you can get a reduction or stoppage on the leak.

 

[kloudie1]

I can't find a spec for tightening the top fitting either.. I do see a spec for the big nut/fitting that it screws onto.. that is 29-32 ft lb. It has an o-ring seal under it which, if it leaked, would have diesel on the pump body around the nut/fitting, but not under the top cap nut that secures the fuel line to the nut/fitting.. That seal is a tapered cone that has to be clean and scratch free.. You can fold a tissue and see if it wicks diesel from under the cap, or from the base of the nut/fitting (delivery valve spring holder) indicating a bad o-ring..

 

[NYSail]

My last boat had a 3HM35f with a shop manual that told everything from torque specs to what beer to drink when fixing a certain part. My new 4JH4E has a pamphlet type book. Anyway Dig into the manual. However you should get new copper crush washers before you do it and start replacing them. And while at it replace the hose you are working on. Once washers are damaged they are spent. In a pinch you can heat and reuse but I rather replace and have ample spares. If you can’t find the specs replace washer and snug them. Also be careful with bleed screws...... never man power them. Snug them unless you know torque.

Good luck!
Greg

 

[justsomeguy]

My last boat had a 3HM35f with a shop manual that told everything from torque specs to what beer to drink when fixing a certain part.

Would you think the torque specs might be similar?
Am I drinking the right beer?

 

[NYSail]

If I had that page I would tell you. Only cut out the beer / part page before I sold her. Sorry dude. Gentle snug until you know.......

 

[justsomeguy]

Only cut out the beer / part page before I sold her.

Priorities. I understand completely.
I've got a 3HM35F service manual on the boat. May be able to respond soon with specs.

 

[Mike Oldak]

Priorities. I understand completely.

I loaned my cousin a torque wrench to replace his engine bearings.He torqued them to spec but then added 50% more to be sure. disaster

 

[hunter34austin]

thank you for all the helpful suggestions - especially the beer

I've ended up hand tightening the first fuel line from the front a bit more. That was the only one I could reach with a regular 17mm wrench. And it looks like that was the issue. All good and tight now.