Lisle 75500 Combustion Leak Detector<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Checks for combustion leaks caused by bad head gaskets， cracked blocks， and cracked or warped heads</li><li>Fluid changes from blue to yellow when exposed to combustion gases from the radiator</li><li>With the engine running， the vehicle vacuum or the vacuum pump draws vapors through the indicating fluid for testing</li><li>With the engine running， the vehicle vacuum or the vacuum pump draws vapors through the indicating fluid for testing</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41kgygOIsYL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/51RUHnfgPgL.jpg" noproxy>