Piston Ring: Service and Repair

Piston Rings

Removing







• Typical piston shown.

- Remove the piston and connecting rod. Refer to => [ Piston and Connecting Rod ] Removal and Replacement.


To avoid damage to the piston rings, they must be removed in the following order:

• No. 1 (upper) piston ring (1)

• No. 2 (intermediate) piston ring (2)

• Oil ring upper side rail (3)

• Oil ring lower side rail (4)

• Oil ring expander (5)







• Typical piston shown.

- Remove the No. 1 (upper) piston ring using a ring expander tool.

- Remove the No. 2 (intermediate) piston ring using a ring expander tool.







• Typical piston shown. Do not use a piston ring expander to remove the oil ring side rails.

- Remove the oil ring upper side rail.

- Remove the oil ring lower side rail.

- Remove the oil ring expander (1).

Installing







• Typical piston shown.

- If required, fit new rings to the piston. Refer to => [ Piston Ring Fitting ] Piston Ring Fitting.


To avoid damage to the piston rings, they must be installed in the following order:

• Oil ring expander (5)

• Oil ring lower side rail (4)

• Oil ring upper side rail (3)

• No. 2 (intermediate) piston ring (2)

• No. 1 (upper) piston ring (1)







• Typical piston shown. Do not use a piston ring expander to install the oil ring side rails.

- Install the oil ring expander (1).

- Install the oil ring lower side rail by placing one end between the piston ring groove and the oil ring expander. Hold this end firmly and press down the portion to be installed until the side rail is in position.

- Install the oil ring upper side rail in the same manner as the lower side rail.







• The No. 1 (upper) piston ring (1) and No. 2 (intermediate) piston ring (3) have a different cross section. Install the rings with manufacturers I.D. mark (dot) (2) facing up, towards the top of the piston.







• Typical piston shown.

- Install the No. 2 (intermediate) piston ring using a ring expander tool.

- Install the No. 1 (upper) piston ring using a ring expander tool.

- Rotate the rings around the piston, the rings must rotate in the grooves with out binding.







- Position the piston ring end gaps as follows:

• Oil ring expander gap (5)

• Oil ring lower side rail end gap (4)

• Oil ring upper side rail end gap (1)

• No. 2 (intermediate) ring end gap (5)

• No. 1 (upper) ring end gap (2)

- Install the piston and connecting rod. Refer to => [ Piston and Connecting Rod ] Removal and Replacement.