Ello, Can anyone see a problem with me doing away with the cylinder head air bleed non return valve, The reason for the question is as everyone knows they do in head gaskets, and you allways hear about hot spots and thermal stress etc causing it. My point is when I changed the gasket on my rover 100 "metro", I thought the thing was blocked, so I poked a steel rod into it and sent the internals flying down the drive way never to be seen again. The entire cooling system was just solid gunk, like mayonaise, I had to strip every pipe off and clean them out before I could get any water into it. Engine rebuilt and refilled, and forte bio degreaser added, Run it at temp on the driveway for about 45 mins, drained and filled with coolant, and since have done 8 thousand miles without a problem. My point is, that there was never going to be any circulation through that tiny pipe after rebuild, but now it is constant, which ensures the head is allways free of air and hopefully hot spots, does anyone have a good reason why I should not do this with my freelander, any advice appreciated.