Block Check Leak Tester Pinpoints Combustion Leaks

Hasting’s Model 3520 Block Check Leak Tester quickly and easily finds combustion leaks. Tests Gasoline, Propane, Alcohol or Diesel type engines with the same fluid, and can check for combustion leaks caused by bad head gaskets, cracked blocks, cracked or warped cylinder heads. Fluid changes from blue to yellow when exposed to combustion gases that leak into the cooling system.

Hastings Inc.