6G72 Water pump rear tube O-ring. Where to buy replacement?

[mightymaximus]

I'm changing my timing belt which broke on my MM, and I can't find a parts house that correctly identifies the O-ring that is on the tube that goes to the back of the water pump. The tube is in between the two banks of cylinders under the intake manifold.
I bought a kit that included a new pump, cam and crank seals, as well as the water pump gaskets, except that O-ring. It doesn't seem to be a standard diameter, or thickness.:bang:

I have looked at Auto Zone, Orielly, Pep Boys, and Rock Auto, they all find some huge o-ring that is not the right one.

Any help identifying what that O-ring part number, or even what I is called, would be helpful.

That is the last part I need to put this thing back together. I'd like to replace it, since you have to take some much apart just to get to it, and the truck has 250K so it is probably due.

Thanks in advance for all the info that is here and the help already given to my previous questions.

[85Ram50]

You didn't post a year so here is a link https://www.mitsubishipartscentral.com/
They usually have the diagrams and part numbers even if they don;t have the part.
On my 85 that Oring did not seal when I put in a new head pump timing belt etc and I had to get some red gasket maker on my finger and rub it around the spot where the tube comes out of the WP

[claych]

mightymaximus (http://www.mightyram50.net/vbulletin/member.php/3215-mightymaximus),
?Auto or Manual trans?
Thx.

[mightymaximus]

@85Ram50
Thanks for that link!
@claych
The truck is a 94 with the V6 model engine in my profile description, and a manual trans 4x4.
The O-ring is about 13/16" outer diameter and 1/8" thick.
I have included pics to show detailed dimensions with a measurement caliper and where it is from in the cooling system.

[claych]

Thx, :)
I got that, I was asking so I could ck the pipe part #'s between the auto/manual
equipped vehicles as there are 2 different #'s.
Your good to go, only the auto# is obsolete.

Now onto the o rings, (really like the caliper btw,metric,thousands& 64ths all in one!!),
I 'think' I have located a non -Mitsu source, as My dealer connect has not gotten back to Me...
Could I impose for an I.D. measurement ? ,
Thx!

Edit,

Mr Gene Winfield," every day is a school day"
I found out o rings are 'sized' by cross section (cs) & inside diameter(id).
Makes perfect sense as different cs with the same id = many different
outside diameters .

Edit,
8-10$ each # MD030764 or
V4.00X016
(https://www.theoringstore.com/store/index.php?main_page=index&cPath=368_65_169)$1.88 each.


(https://www.theoringstore.com/store/index.php?main_page=index&cPath=368_65_169)