Toledo Combustion Gas Leakage Test Kit 304000Diagnose 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