Test liquids for cylinder head leak tester – CO2 tester.
A special test liquid is required to carry out the test process. This shows a color change/reaction from the blue original color to yellow/green color, so a leak is definitely proven. An increased CO2 content in the air cushion of the test device causes this discoloration and thus proves that there is a leak.
There is a special rinsing liquid to rinse the device perfectly clean after use.