Cooling system Checking coolant antifreeze and corrosion protection Note: Use only pure fresh water that is free from parti- cles, sludge and other impurities. Tools Illustration Refractometer 305 523 1. Pour a small amount of coolant into a con- tainer and check that the coolant is pure and clear. 138008 2. Change the coolant if it is contaminated or cloudy. 3. Measure the antifreeze and corrosion inhibi- tor content with a refractometer. The following rules apply to ethylene glycol- based coolant: The antifreeze and corrosion inhibitor content must be minimum 35 percent by volume for corrosion protection to be sufficient.
An antifreeze and corrosion inhibitor content greater than 55 percent by volume impairs the ability to protect against frost. If ice forms in the coolant, there are disrup- tions initially, but there is no immediate risk of damage. The engine should not be subject- ed to heavy loads when ice starts to form. 00:23-02 en-GB 25 © Scania CV AB 2016, Sweden