Morning all, low coolant warning came up on the dash yesterday, lifted the bonnet to smell hot coolant and found it sprayed all over the back of the fan and on the front of the engine. Called the AA who came out promptly and pressure tested to 15 bar, no loss of pressure but plenty of coolant on the ground, he suspects a leak from the water pump. I have done a search on here and water pumps on a TDV6 don't seem to be a problem. The car is now at a local indie awaiting inspection.

They can fail (and have had some reports of this). Usually bearing wears. They are pretty straight forward to change once the Viscous fan is off.
Just need to undo the three E-Torx boltcs on the water pump for the pulley, then release the Aux Belt tensioner and remove the belt.

then undo the 8mm (might be 10 mm) bolts holding the water pump on.
You need to try to find a way of catching the coolant that's released as its very bad for water courses.
Then re-fit the new water pump. Make sure it is fitted square and you don't nic the rubber o-ring. New water pump is about £50 and new o-ring is about £25!!! (don't ask how I know this ) Someone who did this had already thrown the old water pump away so I they couldn't use the old O-ring.

Then refill with 50/50 coolant (OAT) and bleed the air out.

Sequence is bleed air first (one on top of the engine area at the front and the other on the coolant bottle. Then rev to 3000 rpm for one minute, idle for 5, rev to 3,000 for one minute, idle.

I've found it more effective to bleed whilst someone else is revving the car as the water pump generates more pressure. Bodsys Brake Bible
Software Updates Contact me
RRS Timed Heat/Remote kits - Contact me
BAS Engine Re-maps/ EGR Blank EuIII and EuIV
Clock On The Dash/ SNOTM /3Flash / BT Update /Service Reset/Error Codes read\ Gearbox Reset
See it HERE

Many thanks for the detailed response Bodsy, I'll report back with an update later..