The Performance Tool leak down test kit tests how much air leaks from an engine's combustion chamber. Performing a leak down test will show where the loss of compression is, such as intake or exhaust valves, head gaskets, rings or pistons, or the engine block. This kit features an adjustable pressure regulator with 14mm flex hose and 12mm, 14mm, and 18mm thread adapters. Quickly diagnoses internal engine problems like bad rings, valves, and leaking head gaskets Leak down tests are more accurate than standard compression tests for engine diagnostics Pressurized air is applied to each cylinder and then monitored for a level of leakage Dual 2-1/2 in. gauges have chrome bezels and rugged protective outer boots Compression gauge reads 0-140psi and 0-10 bar. Leakage gauge reads 0-100 percent Pressure-regulated manifold, with quick couplers, 24 in. long 14mm flex hose Also includes 10mm, 12mm, and 18mm thread adapters for most gas engine applications Rugged, blow-molded storage case with removable lid keeps components organized