Piston: Testing and Inspection

Piston, Rings and Cylinder Bore, Checking





Piston Ring Gap, Checking

Special tools, testers and auxiliary items required
^ Feeler gauge

Test Sequence
- Push ring squarely from above down to approximately 15 mm from bottom end of cylinder. To do this use a piston without rings.








Ring to Groove Clearance, Checking

Special tools, testers and auxiliary items required
^ Feeler gauge

- Clean ring groove before checking.








Pistons, Checking

Special tools, testers and auxiliary items required
^ External micrometer 75 to 100 mm

- Take measurement approximately 6 mm from lower edge of piston skirt and offset 90° to piston axis.

^ Deviations from nominal dimension: 0.04 mm





Cylinder Bore, Checking

Special tools, testers and auxiliary items required
^ Internal dial gauge 50 to 100 mm

Test Sequence
- Measure diagonally at 3 positions transversely - A - and longitudinally - B -.

^ Deviations from nominal dimension: 0.08 mm.

Note:
^ Measurement of cylinder bore may not be performed when the cylinder block is mounted on engine and transmission holder VAS 6095 or holding fixture VW 540, false measurements are possible.