Re some grease coming out t'top cap, isn't this actually desirable? If the top cap was completely air-tight, how would the grease make its way up there - to do so the fresh grease needs to displace what's already there and can surely only do that if the old stuff has an 'exit' route?!

Air tight I think is not possible. The king pin is hollow so the grease travel up the middle to the grease cap. When the grease meet some resistance, it is pushed out through the king pin holes supplying the grease right around the top and bottom bush continuing out where it can, normally between the arm and the hub. Clever design really.

Trying to dig one out like that at the moment

Just like to say that this was a HUGE help for me today, as managed to replace one side being a complete novice

Thanks for your positive feedback. I’m glad it worked for you even being a novice.
The whole point is exactly ‘’how to replace a king pin’’
A petty that the 2cv school (doing other jobs) was killed by so many sceptics.

+1 'tis a shame indeed!

Just done my D*lly's king pins - removing/replacing the pins couldn't have been done using a drift - very tight indeed. Used the "special tool" as shown in the Haynes manual pg 129. Didn't employ freezing the new pin or applying heat to the arm. Thanks to Viking B for his series of pictures & advice.

Changed another one today, this one was much stickier to get out! Have to say, I can't believe the difference i makes, she feels amazing to drive now. Just lovely. Thanks again Viking

I know this is a fairly oldish post but very informative, I was just browsing and not having had the pleasure of replacing mine as yet. I understand they'd been done when I first had the car,having greased them on a regular basis, after 30,000 miles she's just past her 3rd MOT with me without ant problems. I do have a little more play in one side my MOT man only said it's inherent with 2CV's, as mine is not the only one they test I'm not worried.But having considered the replacement I was wondering if anyone has ever put a few turns of PTF tape around the welch plug before banging it home,as a way of sealing the joint from both escaping grease and water ingress.

hi all, i replaced both k/pins 2 weeks ago the pictures and method is exellent , the welch plug leaked a bit of grease , so maybye the ptfe tape idea is worth a try
i did the steering rod ends too one side was totally worn out, dry as a bone, and one of the cups had half of it missing! it wasn,t even mentioned on the mot failure list don,t forget there mneeds to be a rubber cover fitted over the steering ends for the mot now!--
i got all the parts from burtons