got hot air when engine under load but now all ok new thermostat and bled the system,,fans all working now done what you said and stripped the fans and brushes were stuck in holders so gently slid them out cleaned with a fine bit of sand paper was a bit of a fiddle getting all 4 brushes to stay in holder but if you put a piece of wire through the holder to keep in place put the motor back on then remove the wires it makes it easier otherwise you will need the patience of a saint ,thanks everyone for all your advice