Checking cylinder diameters
Accurately measure the cylinder diameters. Measurements are taken with a bore gauge in three zones both in the transverse direction "A" and in the longitudinal direction "B", as shown in the diagram.
In cases where wear exceeds the permissible value by more than 0.04 mm, repair the cylinders to the nearest repair size and install pistons of the corresponding repair size.
Cylinder blocks are marked at the factory depending on the diameter of the cylinders and pistons. The corresponding mark is located near the generator mounting location.
(The text is based on materials from the website AudiManual.ru)