1990 V12 5.3 expansion tank removal

[BigBlueCat]

After noticing a slight seeping from the side of expansion tank ( corrosion from inside), I'm going to change it out. I've got the tank, located the three nuts on the inner wing to remove it. A couple of questions before I start.
1: Will I lose all the fluid or just some and which is the better refill point.
2: Will removing just the front of the air filter box give me enough space to get the tank out.
any thoughts or experiences much apprieciated.

[PaulGover]

You should only lose the contents of the expansion tank.

I usually unplug the connectors in the way and remove the air filter box and filter, that gives much more space. If you've not removed the filter before, take it easy as the seal might be stuck in the lip on the box.

While you're doing it, it's worth removing the overflow catch tank hidden behind the wheel arch closing plate. It will probably be full of all sorts of gunk from many years overflow and ageing antifreeze etc. The rubber hose to it may well be blocked.

Also, check the hoses, clamps and radiator cap from the expansion tank. If they're damaged or perished they'll bleed air in and prevent the system working properly. If in doubt, renew, as they're cheap.

[BigBlueCat]

Cheers Paul all the pipes.caps,hoses and the over flow catch tank were done last June by KWE, had a full cooling upgrade. It had a full service at the same time so hopefully the filter should be free, but I'll take your advice and be gentle. The only thing we didn't change and it's sods law isn't it was the expansion tank, looked good at the time but you can't see inside can you. At least you've put my mind at rest regarding coolant lose and space.