NOTE
After the piston and the cylinder have been properly recondi-
tioned, including proper "deglazing" and cleaning of the cylinder
bore, the use of an abrasive or lapping compound to seat the
piston rings is not necessary and is not recommended.
After the cylinder has been thoroughly cleaned, apply compres -
sor lubricating oil to the cylinder bore and replace it on the
compressor frame, making sure a new gasket is used between
the cylinder and frame. Extreme care must be used when re-
placing the cylinder over the piston rings to avoid distorting or
breaking the rings. The use of a piston ring compressor is
highly recommended. Replace the cylinder attaching screws,
tightening each screw to the recommended torque value.
5-7.5.12. Apply a liberal amount of compressor oil to the cylinder bore and then replace
the air head on the cylinder, making sure a new gasket is used between the air head and the
cylinder. Replace the air head attaching screws, tightening each screw to its recommended
torque value.
5-7.5.13. After new replacement piston rings have been installed, the compressor should
be operated for at least 10 hours at full load before checking for proper air delivery and oil
consumption.
scraper style ring, slip the ring into the ring groove, making sure that the bevel is toward
the head of the piston and the undercut groove is toward the bottom of the piston. The "H"
type ring is always installed in the bottom ring groove.
5-7.7. "M" Type Rings - Install the "M" type or four-piece, ventilated, chrome plated steel
rail style ring by first placing the expander in the ring groove with the free ends toward you.
Push the ends of the expander to the inside of the ring groove, butting the ends together.
Make sure the ends of the expander do not overlap. Caution: do not clip or cut the ends of
the expander or the tension will be destroyed. Thread one of the two steel rails over the ex-
pander and into the bottom side of the ring groove. This rail will hold the expander in posi-
tion. Again check to be certain that the ends of the expander are not overlapping. Place the
open separator over the expander and adjacent to the steel rail, with the free ends of the
separator away from you. Thread the second steel rail around the expander and into the re-
maining clearance at the top of the ring groove. Again be certain that the free ends of the
expander are butted together and are not overlapping.
5-7.8. "B" Type Rings - Install the "B" type or single-piece, taper-faced style compression
rings by placing each ring into its groove, starting with the bottom compression ring and
working towards the top. Each taper-faced style compression ring is identified in some man-
ner, usually with the word "top", the letter T, a dash, a dot or a paint mark to aid in making
sure that the ring will be positioned properly in the ring groove. That is, each compression
ring must be installed so that the top of the ring is towards the head or top of the piston.
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