Why? The cylinder leakage test is usually performed to find out why a cylinder has low compression. Where is the compression going? This test will tell you where!
You'll Need Hand Tools Cylinder Leakage Tester Running Vehicle (see instructor)
Procedure Warm up vehicle to operating temperature
Step 1 WEAR EYE PROTECTION!!!
Step 2 Locate and remove all spark plugs Mark wires to ease reinstallation
Step 3 Without attaching to vehicle yet, hook up air pressure to tester and adjust to 100%. Put your finger over the spark plug thread fitting and block the air flow, the gage should go to zero%. If not, adjust till it reads zero. Let your finger off and the gage should go back to about 100%. Adjust Here
Step 4 Disconnect tester from air Screw cylinder leakage tester into spark plug hole Connect air to tester Turn engine clockwise to Top Dead Center (TDC) or until lowest leakage % is reached on gage.
Step 5 Listen for leakage at the following 4 places: Exhaust (tail pipe) Air intake (open air filter) Crankcase (open oil cap) Radiator (top opening) Note findings on your task sheet Repeat for each cylinder
What does this mean? Exhaust (tail pipe) Air intake (open air filter) Crankcase (open oil cap) Radiator (top opening) Exhaust Valve Leakage Intake Valve Leakage Piston or Rings Leakage Head Gasket Leakage (or cracked head/block)
Step 6 Reinstall spark plugs and wires Start vehicle to assure correct plug wire installation
Results Determine if leakage is within factory specs (Look it up in All-Data) Leakage should never differ more than 15% from highest to lowest cylinder What repairs do you think might be needed? What repairs do you think might be needed?
Put Away All Tools and See Instructor for Assessment and Signature