Hi..water pump started to leak,have replaced it..then expansion tank split..this might be problem....the one fitted had 2 small hose connections at top and 1 middle size @ bottom..have replaced with tank that has one hose @top (hose connect to injector manifold) radiator overflow hose connects @ bottom along with middle size hose..since replacing Head gasket has GONE west ...is it wrong expansion tank to blame or just one of them things ...cheers