Kubota tractor injection pump leak

[obsolete]

Trying to help a friend figure out what this part on a injection pump is and why it's leaking fuel. The tractor is a Kubota 5500DT wheel tractor, SN 10302, with the D 3000A engine, the pump is a Nihon-Cav SN 07940TW, DPA19932F002.
The part that is leaking fuel is the 2 inch diameter disc on the top of the pump that looks like a little hand wheel, it's leaking from a hole in the center of the top.
Looks like a bleeder valve with some sort of relief or vent built in, he can find no specific reference to that part in his books.
I have determined that the part is a Damper, still unsure of it's function, I see many available but cannot tell if the similar looking ones will have the same threads, as most listed are for Lucas.

Thanks

 

[Welder Dave]

Hopefully thepumguysc see's this. If anyone would know it would be him.

 

[Coaldust]

It’s just a dampener like you said. It smooths out the injection pulses. Has a rubber type diaphragm. It’s leaking out the weep hole because the diaphragm is old. There is a check ball inside the fitting.

The check ball will fall out and you will loose it. Then, you will be sad.

EBay, Amazon, many other on-line places sell them. $50 or so.

Good luck and don’t drop the ball.

 

[thepumpguysc]

Do u still need the part number.??

 

[obsolete]

Do u still need the part number.??

Yes please.

 

[thepumpguysc]

CAV/Delphi..
7139-159A. Side Dampner
7139-159B. Bottom Dampner

Good luck and lemme know if you need help finding one..
PS: The side Dampner does NOT have a ball.. and it seals to the pump with a copper gasket..
IF u can find one that comes with a gasket, get it.. cuz the old one will probably leak..
Good luck

 

[obsolete]

Thanks for the help, look like the 7139-159A is the part, ordered today.