• Single Gauge Leakdown Tester
• Designed to check the amount of combustion chamber leakage in a 4-stroke engine
• Speeds up troubleshooting & helps to isolate bad components
• Gauge accurately displays the total percentage of leakage past the rings, head gasket, intake and exhaust valves
• Tests at 80 psi cylinder pressure; minimum air source of 90 psi required
• Includes 1/4 inch male industrial quick connector
• Meets FAA leak down test specifications for cylinders below 5.00 in. (127 mm) bore diameter
• Hose and adapter fits 10, 12, and 14 mm spark plug threads
• Includes high-quality regulator and gauge
• Includes convenient molded tray
• Instructions included

Note: When using this instrument the orifice inlet pressure is maintained automatically by the pressure regulator. A single gauge works well as long as leakage flow is much less than regulator flow. Any error in the input pressure will produce a corresponding error in the reading. As a single gauge instrument approaches 100% leakage, the leakage scale error reaches maximum. This may or may not induce significant error, depending on regulator flow and orifice flow. At low and modest leakage percentages, there is little or no difference between single and dual gauges.

 

No engine will have perfect sealing with 0 percent loss. Five to 10 percent loss indicates an engine in great to good running order. An engine between 10 and 20 percent can still run OK, but it’ll be time to keep an eye (or ear) on things. Above 20 percent loss and it may be time for a rebuild. Thirty percent is a major problems. The percent of leakage should also be consistent across the cylinders. Any great differences indicate a problem in that cylinder.
Beyond getting an overall picture of engine condition, the engine leakdown test is an excellent way to pinpoint where problems are before tearing down the engine. Listening for where the air is escaping by ear can isolate the problem.
    •    Intake valve : Air whistling out of the intake, carburetor or throttle body indicates a leak at the intake valve.
    •    Exhaust valve : Air heard hissing out of the tailpipe, turbocharger or exhaust manifold means an exhaust valve leak.
    •    Piston rings : Whistling or hissing out of the PCV valve, oil filler cap hole or dipstick tube means the air is pushing past the rings. Suspect ring or cylinder wall wear.
    •    Head gasket : Air bubbles in engine coolant seen at the radiator filler cap could mean air escaping into the coolant past the head gasket.
    •    Cracked cylinder head : Bubbles in coolant or coolant being pushed up out of the radiator neck can also indicate cracks in the cylinder head or cylinder walls.