You will need a new crush washer. They are a one time use item. Not all engines have them, tho.
On the bolt there should be a machined slot for a rubber "O" ring to fit in, if you don't have one, find one.
Replace the primer also, or at least replace the fuel lines going to it.

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83 SD

84 CD

those new style pumps are soooo much nicer i just got one for my 240d after two years of the old squirting one. i dont even have to pull it up!

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

I have an O ring in the garage, but since an O ring wasn't on the bolt or anywhere else, I didn't use the new O ring. There was a black band around the mid-section of the bolt. It wasn't a ring though as it was flush with the bolt; had flat sides. Didn't look like it was meant to come off or replace, so I left it.

Regarding the primer, I pumped until fuel spilled out of it. Should I keep pumping? that seem's unnecessary to me...but what do I know.

What are the spec's of the copper crush washer? And can I do/replace anything now that will allow me to never have to use a copper crush washer again? they're too hard to find.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

If you previously filled the fuel filter I ment use the priming pump before you start the car. It is hard to describe it but when you pump with the primer pump and the are starts leaving the IP you well he a buzzing, deep squeeling sound and keep pumping some more and at that point the air is out of the IP housing.
If air gets up into the Fuel injection lines between the IP and The Fuel Injectors it takes too much cranking with the engine to purge it. As I said if you loosen some of the Fuel Injectio Line nuts up by the Fuel Injectors ie bleed out fast.
Check this PDF below to see the factory method of bleeding the air out after a filter change:
http://www.pauldrayton.com/uploadfiles/merc/Service/W123/w123CD2/Program/Engine/617/07_1-140.pdf

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84 300D, 82 Volvo 244Gl Diesel

Great, thanks. I'll do this tonight. I pumped before starting the car, a lot. The prefilter filled with fuel and the pump became hard to move, so I thought that was sufficient.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)