Piston Ring: Service and Repair

FITTING PISTON RINGS

Check Gap On Piston Rings:

1. Wipe cylinder bore clean. Insert ring and push down with piston to ensure it is square in bore. The ring gap measurement must be made with the ring positioning at least 16 mm (0.63 inch) from bottom of cylinder bore. Check gap with feeler gauge. Refer to Piston Ring Specification Chart.

Piston Ring Groove Clearance:

2. Check piston ring to groove clearance; Refer to Piston Ring Specification Chart.

INSTALLING PISTON RINGS

Piston Ring-installation:

1. The No. 1 and No. 2 piston rings have a different cross section. Install rings with manufacturers mark and size mark facing up, to the top of the piston.

CAUTION: Install piston rings in the following order:

2. Oil ring expander.
3. Upper oil ring side rail.
4. Lower oil ring side rail.

Side Rail-Installation:

5. Install the side rails by placing one end between the piston ring groove and the expander. Hold end firmly and press down the portion to be installed until side rail is in position. Do not use a piston ring expander.

Upper And Intermediate Rings-Installation:

6. Using a piston ring expander, install No. 2 piston ring and then No. 1 piston ring.

Piston Ring End Gap Location:

7. Position piston ring end gaps as shown in.
8. Position oil ring expander gap at least 45° from the side rail gaps but not on the piston pin center or on the thrust direction.