Teflon Piston Ring Replacement

1. Remove old piston rings by carefully cutting ring with a knife or other sharp tool, holding blade almost flat with piston surface. Be careful when cutting ring to avoid injury. Also, be careful not to damage piston or groove while cutting the ring.
2. Clean piston and groove with a recommended cleaning solvent and force dry with compressed clean dry air.

Fig. 39 Installing Teflon piston ring on ring installer guide:

3. Set piston on end on a clean flat surface and place ring installer guide on end of piston, then install Teflon ring on ring installer guide with dished or dull side down and glossy side up, Fig. 39.

Fig. 40 Installing Teflon piston ring on piston:

4. Push ring installer down over the ring installer guide to install Teflon ring into piston groove, Fig. 40. If Teflon ring is improperly positioned, it can be correctly positioned using a blunt-edged tool that will not damage piston. Do not store installer guide inside ring installer, as this will cause stretching and weakening of ring installer segment retainer O-ring. After installing piston ring, remove installer guide from ring installer.

Fig. 41 Turning piston & ring assembly into ring sizing tool:

5. Lubricate piston ring area with refrigerant oil and rotate piston and ring assembly into ring sizer at a slight angle, 41. Rotate piston while pushing inward until piston is inserted against center stop of ring sizer. Do not push piston and ring assembly into ring sizer without proper positioning and rotating as described above, as ends of needle bearings of tool may damage end of piston.
6. Rotate piston and ring assembly several complete turns, until assembly rotates relatively free in ring sizer.

Fig. 42 Gauging piston ring:

7. Remove piston and ring assembly and wipe end of piston and ring area with a clean cloth, then push piston and ring assembly into ring gauge, Fig. 42. Piston should go through ring gauge with a force of 6 lbs. or less without lubrication. If not, repeat steps 5, 6 and 7.
8. Repeat above procedure on opposite end of piston. Do not place piston down on a dirty surface where dirt or metal chips can become imbedded in Teflon ring.
9. Lubricate both ends of piston with refrigerant oil before inserting piston into cylinder bore. Use care to avoid damaging Teflon ring when installing piston into cylinder bore.