COLLAR-GUIDE 2841503 - Caterpillar

piston rings may have a Keystone design, which is tapered or the piston rings may have a square cut design. A 325-8417 Piston Ring Groove Gauge or a 325-8421 Piston Ring Groove Gauge is used in order to check the piston's ring grooves with the Keystone design. A 5P-3519 Piston Ring Groove Gauge Gp is available for checking piston ring grooves with straight sides. For instructions on the use of the gauge, refer to Reuse And Salvage Guidelines, SEBF8059, "Procedure for Measurement and Inspection of Pistons". Note: Some pistons have a larger diameter, which depends on the engine arrangement. Make sure that the properly sized piston ring groove gauge is used with the pistons that have the keystone style piston.