With engine running, place tester on coolant compensation tank. By operating the rubber bellows the air will be sucked out of the coolant compensation tank - no coolant must be sucked up in the process. If the blue fluid in the upper chamber of the test device turns yellow the cylinder head seal or the cylinder head is leaking.
Inspect Procedure: the transparent test device cylinder contains a blue reaction fluid which turns yellow when exposed to air containing the slightest amount of carbon monoxide. When the fluid is exposed to fresh air it regenerates, i.e., turns blue again. The fluid can be tested by exposing it to fumes from the exhaust pipe, which should cause it to turn yellow. |