Hi all, I will be swapping the coolant expansion tank on my 08 XF SV8(4.2 SC) out for a new one as on the original the top plastic tube that connects to the hose has broken.

My question is, is it preferred to flush out the system or just replace the coolant tank and top up with new coolant?
If flushing the system, what would be the correct way to do so? And how I would I bleed the system?

Any help would be greatly appreciated!
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Unless your coolant is old you can just replace the tank and top up. I've just replaced the tank on my SV8 a month or so ago (but my coolant was changed only a few K ago when I replaced a failed SC pump).

Its supposed to be a long life coolant for 10 years/150,000km but people seem to recommend changing it every few years or 50K, or you think there might be contaminants in the coolant. I would avoid using any chemical flush as some of the flush products don't like being mixed with the specific coolant used in the SV8 and its a pain to get 100% of it out of the coolant system, esp the SC, plus you might remove some scaling and build up that is keeping your old connections sealed.

If you want to drain it completely there is a drain point on the bottom of the radiator, drop the air deflector under the engine and you will see it on the LH side. There is a bleed screw above the RH headlamp that'll let air in/out of the supercharger cooling system.

Make sure you use the right coolant when filing it up, its supposed to be Ford spec WSS-M97B44-D for the SV8 (it usually comes as an orange concentrate that you need to mix with deionised/distilled water).

To fill and bleed just pour in the correct coolant mix into the header tank, let the air out via the bleed screw above the RH headlamp. Give it time to settle and push the air pockets out. Personally I run the engine for a minute with the expansion cap off to burp out any major bubbles, top up and cap it then let it get to operating temperature where the thermostat should open, let it cool and top up again, that seemed to be the most effective way to get all the air out of the SV8 cooling system.

Keep an eye on it over the next few days as air bubbles in the water get forced out and it drops a bit.

 

That's extremely helpful thank you! I should be right to just swap out the tank than because the coolant currently in the vehicle is very clean looking. I shouldn't loose any coolant if much at all aside from what's in the tank should I?

I'm also wondering, because I'm having trouble finding it in Oz, but is there another recommended power steering I could use aside from Pentosin CHF202? It's quite difficult to find.

 

You won't loose much, but what you will find is that the hoses you disconnect from the expansion tank will naturally want to drop to just below the height of the engine, which will draw out any coolant that is higher up, e.g. the SC and engine thermostat. Its only under atmospheric pressure so if you can lightly clamp the hose or plug it with something then you won't loose much. If you drop one of the hoses down the side of the engine it will dump a bucket load of coolant over the aircon compressor.

In terms of the power steering fluid I'm not sure, I've just topped up with CHF 202 (TITAN CHF 202), there might be other equivalents, I'd have to check the owners manual.

 

That's very helpful thank you! I'll look for something to either clamp or plug the hose.

I think I've found an alternative to the CHF202 power steering fluid. It can be used in place of CHF11S, CHF202 or mixed as it's virtually the same or equivalent at least.