Preventive maintenance
68 810770 Operator Manual Echion
13. Put the check valve face or the low-pressure poppet face flat on the lapping paper and move it
back and forth. Use light pressure. Do this procedure until the face is smooth and flat and has a
mirrorlike finish.
CAUTION
Do not rock the parts or use too much pressure. Doing so can cause damage to the
part faces.
CAUTION
Keep the low-pressure poppet and the poppet retainer clean. Grease can cause the
poppet to stick.
Do not put grease or lubricant on the check valve face or in the cylinder bore. These
components are designed for dry contact.