Expansion Bottle

[dln1978]

Could someone please tell me, when the water overflows into the expansion tank when the engine cools is that water supposed to be sucked back into the engine.

If it is, could anyone give any suggestions why this would not happen?

[Sancho]

Yes, the purpose of the expansion bottle is to take excess coolant as it heats and expands, then store it so that the engine can suck it back in as it cools.

I would have thought the most likely explanation for it not doing that would be that the pipe that draws coolant back out of the expansion bottle is not connected.

Another possible explanation is that you have a leak somewhere (possibly a hole on the top of the radiator) that is giving the engine the option of drawing air in instead.

Check the top of the radiator for holes, or even white marks where there might be tiny holes you can't see and make sure your expansion bottle is fine, as in this diagram:

http://www.hiluxsurf.co.uk/forums/at...6&d=1216375250

[MattF]

As Sancho mentioned, check that hose is connected and that it isn't blocked. Pop a new rad cap on too.