Lehman bleed screw question

Thought I'd start a new thread about this issue (leaking bleed screw was the other topic).

I ordered new bleed screws with copper washers from ADC. Turns out they were for the secondary fuel filter bleed screws. Called and spoke to Brian (what a nice guy!) and he said as the bleed screws were iron like the fuel injector housing he's probably only sold 15 of them over they years. Most likely because folks dropped them in the bilge. He suggested getting new copper washers.

Turns out both sets (two each) of injector bleed screws on my engines do NOT have any copper washers. Instead, they have these very thin, soft (aluminum?) washers. See attached image. The guilty leaking bleed screw had one that was virtually gone, which would account for the metal shavings I found at the head of the screw.

So my question is this: Are these soft metal "washers" normal? Methinks I will remove the remains of the faulty/leaking washer and replace with the new copper washer and see how it goes. Just want to know if I'm supposed to have the other washer on there, too.

Brian also told me that the oil level/fill screw on the face of the fuel injector also uses the same copper washers as the bleed screws.

Only one washer necessary.

I think those aluminum washers are the same as used on the bolts holding the fuel return tube on the injectors. The copper ones look too big.

That copper washer looks like the ones on the bottom of the injectors when you repeat them.

Yes, that washer is too big, will require too much torque to seal and one thing is certain, the threads in the body of the pump are fragile and will eventually strip out.

For those of you who have copper washers, they should be replaced or annealed every time before reinstalling the bolts.

To anneal, heat them with a torch until they are cherry red and then quench them.

Follow up post (to complete the story).

I ended up ordering new copper washers from Seastrom Manufacturing in Idaho. They have a LOT of washers. Got 10 for 5/16 screws, half-inch OD. They weren't cheap ($3.90 ea), but they fit perfectly and NO MORE LEAK!

And thank you, Xsbank. I annealed them prior to install.

The reason copper is used is because it's a soft metal and compresses making a better seal. And don't over tighten the bolt/screw. That's what destroys the internal threads.

Lepke said:

The reason copper is used is because it's a soft metal and compresses making a better seal. And don't over tighten the bolt/screw. That's what destroys the internal threads.

Click to expand...

Fortunately there is enough thickness to install a helicoil.

Would one of those orange fiber washers do the trick? - -they certainly compress and there isn`t a huge amount of pressure there, however I don`t know their compatibility with diesel

Greetings,
Mr. M. I'm guessing the silver washers are the originals and are indeed aluminum. IMO aluminum seals as well as copper for this purpose. Annealed al' might be softer than annealed copper.

Aluminum seals just as well as annealed copper. That's why all my 60s British motorcycles rely on aluminum washers to maintain their oil tightness.


Oh... wait.

RT Firefly said:

Greetings,
Mr. M. I'm guessing the silver washers are the originals and are indeed aluminum. IMO aluminum seals as well as copper for this purpose. Annealed al' might be softer than annealed copper.

Click to expand...

We used to anneal the copper washers on Bosh injector lines if we didn't have the right washers for the banjo bolts. Most people don't know how to do that.
I would put them on a fire-proof surface (brick, concrete, metal, etc.) and use a propane torch to heat the washer. You can see it change color as you heat it up. If you heat it up too much, it will melt, so don't go that far.

Annealing copper softens the metal up, since clamping it down under the bolt "work hardens" the copper with each time. So, as time goes on, it seals less and less. Remove the washer, anneal it and replace and you'll be surprised how well it work.

If you heat it too much, you'll be surprised too...