Thank you for your replies
The chemical test, involves effectively a big pipette with a coloured chemical in, which is put into the radiator hose (where you put the the radiator cap on), the engine is then switched on and the bulb at the top of the pippete is pressed a number of times to take in the gas from the radiator/cooling system, the theory is that if there is a mixture of oil and water then the gas will change the colour of the chemical
This has now been done twice and it is proving negative
The other 2 tests have not been done, is this something i will need to do
Regards
Ali