Time to stop the coolant leak.
The V6 makes radiator replacement a bit awkward, but You can squeeze the radiator out if you remove both sidelamps and the bolts behind them that go into the wings, remove the four bolts that hold the plastic nose module to the top of the inner wings, then prop the whole unit forwards using wooden blocks.
The radiator drain was blocked solidly and didn't flow even when fully removed, so I removed the top hose and faced it down into a bucket under the car. This system was originally pretty empty, however I filled it with antifreeze mix recently and intend to refill with more antifreeze, to keep collecting any further corrosion in the system, then will perform a full flush at a later date.
Undo any radiator hose clips you can, tie the top hose out of the way, then unclip the radiator top spring clips and lift it upwards and off the A/c condenser and out.
The original Citroen clips were still on the lower and oil cooler hoses, so I removed the oil cooler hose at the cooler and lifted the radiator out to gain access to remove these.
At which point I was able to see just how badly affected the wiring loom binding was and the scale on the oil cooler spigot.
I have already applied binding tape to the loom here.
A bit of binding and loom tape wrapping later. The oil cooler hose spigot needed a good clean and de-scale. Vinegar, mini wire brush and scotch-bright pad sorted that.
You have to swap the lower hose clips and temperature switch bung over from the old to new radiator and this new one had an additional spigot, which I blocked using an M6 bolt and some epoxy glue.
I cross filed the end threads of the bolt to make it act as a tap and cut threads into the plastic, then removed it and added the adhesive, before re-fitting it.
I cleaned up the temperature switch plug and copper washer, then used silicon sealant to ensure it sealed well. I've left the radiator empty overnight so the sealant cures, before being subjected to water and pressure.
The wiring loom is tethered to the lower hose.
Note, I tied the radiator spring clips back to the bonnet catches, to ensure they didn't catch the new radiator fins, or pipes.
When refitting the radiator onto the A/c condenser vertical locators, you need to splay the radiator clips using a flat bladed screwdriver.
To have enough clearance, lower the radiator into the engine bay by the side of the dipstick tube, then move it over in front of the tube.
Fitting the lower hose is real fiddle from above, but there is just enough space.
Extra spigot on new radiator.
Radiator fitted.
Worm drive clips aren't perfectly round, but will be fine for these hoses and I already had them. You need to ensure you use clips that can be removed readily, otherwise will need to remove the complete nosecone to undo the radiator hose clips.

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