If there is an issue with the valve you are hoping to install, I have a valve from an 89 300 if needed. Just drop me an email.

note: you lost coolant swapping the electric water pump, because of how low it is in the system. Components at the top of the cooling system, rarely cause fluid loss when disconnected for service. You wont lose much.

FYI. That valve is in a pain in the butt spot. You may have to pull the battery to make life easier. If you've done this already (as per your posts) then you should already know how much coolant to expect to lose.

Best of luck.

__________________
85 300D 3 pedal. Current project.
83 300TD (need rear wiper assembly dead or alive)
84 300SD Daily driver
85 300TD almost 400k miles and driven daily.
98 E300D *sold
86 300SDL *sold and made flawless 10 hour journey to new home.