Ever get that anti freeze smell but no big leak? Wonder where it came from? Well you may have a leak in your expansion tank. Replacement part runs about $210 and is not all that hard to do. You will need the following tools:

Needle nose pliers
T30 torx wrench
Flathead screw driver
Vise grip (small or medium)
wine cork (optional)

Remove torx bolt holding tank in place. Size is T30, I believe.

Use the needle nose pliers or the flathead screw driver to pop the odd looking hose clamps on the small water hoses - press down in the divot and the hose clamp should pop free.

Once you disconnect all three small hoses, move the tank out of the way enough to use the vice grip to squeeze the larger hose clamp ears together, and slide the clamp down the hose. This should allow you to work the hose fitting on the bottom of the tank free from the hose. Use a flathead screwdriver if you need to encourage the hose to break free from its spot on the fitting. You may want to use a wine cork to reduce the amount of coolant that will flow from this hose, but it is not critical (See photo). You will probably spill about a quart of coolant during this procedure, nothing unmanageable.

Disconnect the electrical coupling with the flat head screwdiver - pull the wire bailing out and be careful it does not fall free as it is loose. Remove tank; installation is reverse of removal. Check all fittings and top off with coolant. Run engine and check for leaks. Pat yourself on back for saving about a hundred and fifty bucks in labor charges.

 

I've added a link in the "How To" section.

 

Add a turkey baster to your tools list and you can get most of the coolant out of the tank prior to removing the hoses.

 

Nice job, and thanks for the info, just bought a brand new one for my 8 " just in case ", cost £40 in total.

 

Is the procedure the same for a 2004 XK8 base?

 

Similar. Siphon the fluid out of the tank to reduce the mess and reuse the antifreeze.

 

Had to go to the dealer(needed a 2nd key, car came with only $165.00). Service said expansion tank was split. I could' see, or feel it. They wanted $400.00. I bought a new on for $60.00. This will be my 1st project on "Mosby". If I don't screw it up this forum would have saved me a bunch the first month I own it.
Thank you all.