Bettis P/N 127073E
Revision “A”
Page 18 of 37
3.3.29 Install breather assembly (12) in outer end cap (3-80).
NOTE: Individual actuators may not have reducer bushing (14) depending on port and breather
size.
3.4
G2 AND G3 EARLY MODEL PNEUMATIC POWER MODULE REASSEMBLY
NOTES:
1.
Early G2 and G3 pneumatic power modules where equipped with tie bars
that had nuts on both ends of the tie bars (3-20) – double nuts.
2.
Refer to Section 2 step 2.1.4 for the correct installation location for piston
rod (3-40).
3.
THE ACTUATOR MUST BE IN THE APPROPRIATE OVERTRAVEL
POSITION. Confirm over-travel position by observing the guide block
(1-30) is against the inner wall of housing (1-10).
3.4.1
Refer to assembly drawing page 2 of 2 Detail "C". Install one rod wiper (4-10) into inner
end cap (3-10).
3.4.2
Install one rod bushing (4-20) into inner end cap (3-10).
3.4.3
Coat one Polypak seal (4-30) with lubricant and install, lip first, into inner end cap (3-10).
CAUTION:
Install the Polypak seal with energizer ring facing outboard side of inner
end cap (3-10).
3.4.4
Install piston rod (3-40) through inner end cap (3-10). NOTE: The piston rod end with
retainer grooves to be on the outboard side of inner end cap (3-10).
3.4.5
Apply lubricant to two sets of rod T-seal components (4-50).
NOTE: The T-seal is composed of one rubber seal and two split skive-cut back-up rings.
3.4.5.1 Install two sets of rod T-seals (4-50) into the internal diameter seal grooves of
piston (3-30).
3.4.5.2 Install a back-up ring on each side of the T-seal.
3.4.5.3 When installing the back-up rings, do not align the skive-cuts.
3.4.5.4 If the back-up rings are too long and the rings overlap beyond the skive-cuts, then
the rings must be trimmed with a razor sharp instrument.
3.4.6
Coat one D-ring seal (4-60) with lubricant and install into the piston external seal groove.
NOTE: The flat side of the D-ring seal goes down into the seal groove.
3.4.7
Install piston (3-30) onto piston rod (3-40). NOTE: The cast rib side of the piston is to be
facing away from the outboard side of inner end cap (3-10) or position piston (3-30) on the
piston rod so that the retainer grooves are on the out board side of the piston.
