Lehman 120 bleed screw leaking

[Moonfish]

Well this is a new one for us... For the last eight years, about 15% of the time on start-up, I have had to bleed the starboard engine's fourth bleed screw. Usually just takes a couple manual pumps on the fuel pump lever and all was good.

Had to do it today for the first time in months. Went like normal. Couple of pumps and solid fuel. Engine fires right up. On my regular hourly ER check underway, I notice a diesel smell. Turns out I have fuel "squirting" out the bleed screw.

Shut the engine down and removed the screw completely. There are what appears to be small metal shavings at the base of the screw (which is ostensibly a bolt). I think, "wow, maybe that's what has caused the problem all these years." I clean up the screw, and put it back in.

Started up the engine again and fuel is no longer squirting out, but is still leaking out. And the screw is in tight enough, as I don't want to over-torque. So shut it down and went home on one engine.

Anyone else ever encounter this? I'm going to get ahold of American Diesel in the morning and order a couple bleed screws. Of course, I'm HOPING that is going to be the fix, and that the problem is not in the threads in the fuel injector housing...

 

[RT Firefly]

Greetings,
Mr. M. Where is/are these "bleed screws" located on the engines. That's a new one to me...

 

[Moonfish]

Greetings,
Mr. M. Where is/are these "bleed screws" located on the engines. That's a new one to me...

Mr. RT, there are four. Numbers one and two are on the top of the CAV filter housing. Three and four are on the side of the fuel injector pump.

 

[Pete Meisinger]

I think your bleed screws are soft. The fuel injection pump is cast iron. I would get a new screw and tighten it up.

pete

 

[NWSeadog]

Copper washers might help as well.

 

[SoWhat]

very thin cu washers. ADC should stock them.

 

[psneeld]

Actually, my bet is the screws are steel and the pump housing is aluminum.

Thus the threads in the housing are toast.

I stripped my drain plug threads from the housing and pretty sure they were aluminum as I have read before.

I recapped the drain hole and use a bigger screw with an O ring.

Has worked for years and over 1000 hrs.

 

[timb]

mine was leaking after bleeding . installed a new copper washer and good to go .

 

[Moonfish]

Ordered two new bleed screws with washers from American Diesel. Hoping that solves the problem.