Gentlemen:
I have a 2007 SD990 with 16k on the clock. Coolant showed up in the oil and it lost oil pressure so I shut her down. Drained everything. pulled her apart and replaced the coolant pump seal and shaft after reading of this common failure. Replaced all gaskets and seals, buttoned her back up with fresh oil, filters and coolant, and it did the same thing within minutes while just warming up in the garage! Very frustrating after all the work and money. Now what? Is there another spot? A head gasket or something that may have failed? Please help, I want to put a bullet in it like Harley Davidson and the Marlboro Man! Crap... Help?

Are you actually losing coolant?
Has the level dropped in the radiator or reservoir?

I'm just wondering of there was still coolant left in the engine after the first oil change, though to be honest that does seem unlikely.

I'd say that if you suspect the head then next thing would be to pressure test the cooling system to see if it is leaking.

Did you replace the pump shaft and bearings?

Gentlemen:
I actually replaced the oil twice, since I was thinking possibly some was captured somewhere in the system. It is definitely going in from the cooling system somewhere. I did replace all the usual oils seals, and put new seal, bearings, cir-clips,and shaft as well as a factory gasket around the pump housing and the side cover and the main cover, as well as new o-rings on the metal pump tube. I really did not want any leaks.
When I drained it this last time I noticed that there was allot of milky coolant in the tank, but not in the bottom end, but I shut it off as soon as I lost Oil Pressure again, as the coolant changed the viscosity. Crap..... Thanks for the brainstorming guys!

I'm in a similar boat btw.
I believe I have a small cylinder to coolant breach on one of my head gaskets... so shortly I'll be stripping down to leak down test each cylinder to try and prove that there is a leak and also which cylinder it is.

I only replaced the filter once, It was not collapsed or crumpled up although it did not run long. I guess I could do it again, put another new filter in it and more oil and see what happens, but the coolant level did drop in the radiator and went into the oil nearly right away. Sounds like I need to figure out how to pressurize the radiator and see what happens there. No fluid leaks outside the bike, only into the oil once you start it up. Sounds like it is not straight forward where to look next?

There are things you could try, like running with no oil filter briefly to see if you still lose oil pressure quickly, but if you are sure you are losing coolant then that is pretty damming.

There are radiator test kits you can buy that will either pressurise or draw a vacuum in your system. I suspect some local garage/workshops will have one and could test yours for you.

Some on here have had problems rebuilding the water pump, particularly with seating or splitting the shaft seal - suggest checking the water pump again first.