Diagnose cylinder head and gasket leaks by detecting the presence of combustion gases in the cooling system Suitable for testing the cooling system in watercooled engines (petrol, diesel & LPG) Indicates combustion leaks quickly and effectively Blue liquid will turn yellow within 60 seconds with the presence of a combustion gas, subsequently meaning there is a combustion leak present, no matter the size of the leak 250ml detector fluid. Replacement fluid Part No: 304000A Supplied with tapered rubber cone for universal applications, but also compatible with the Toledo cooling system pressure tester kit and its vehicle specific adaptors User guide included