I have had three of these and this black one I have had a long time it’s automatic and happily tows my caravan and I have no desire for anything else I am 70 and the tea has done 120,000 miles .We have just returned from Wales and suddenly it is using water ,at one stage the thermometer needle kept going to the top of its arc and red light coming on it was empty .I have filled it again and I am using it but I can see the level going down again there is no evidence of leaks or whit stuff around oil filler cap .any hel please I’m at a loss Lewis