PISTON AS 1912156 - Caterpillar

Illustration 1 g01115573
(A) Schedule
(B) Schedule
(C) Schedule
(Y) Valve recession in millimeters (inches)
(X) Hours of operation
(1) 0.254 mm (0.0100 inch)
(2) 0.218 mm (0.0086 inch)
(3) 0.152 mm (0.0060 inch)To determine intervals, use the point on the graph in Illustration 1 that is closest to the measurement for each cylinder.For example, the "Valve Data Sheet" (reference section) shows that the increase in the valve stem projection at the initial 1000 service hour measurement shows a valve recession of 0.152 mm (0.0060 inch). This measurement would allow you to use Schedule (C). According to Schedule (C), the next interval for measuring that cylinder is at 5000 service hours. Another cylinder may have a valve recession of 0.254 mm (0.0100 inch). According to Schedule (A), the next interval for measuring that cylinder is at 3000 service hours.When different cylinders require different schedules, the schedule that requires the most frequent measurements should be used for all cylinders. Subsequent measurements can result in changing the schedule that is used. For example, if the first measurement indicates that Schedule (A) should be used, the next measurement should be taken at 3000 service hours. If the increase in the projection is within Schedule (B), then Schedule (B) can be used for the next measurement.Consult your Cat dealer for assistance.