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Repair
22
311238ZAM
Disassemble the Air Valve
1. Perform steps 1-6 under
Remove the Air Valve
,
page 20.
2. See F
IG
. 11. Remove the screws (124), carriage
cover (112), spring-loaded detent (113), gasket
(106), and de-icing control (145).
3. See F
IG
. 10. Remove the retainer pins (111) from
their holes (J). Invert the pins and slide the heads
into the slots on the piston stops (110). Use the pins
to pull the piston stops out.
4. See F
IG
. 11. Rotate the piston valve assembly (119)
so the pins (P) are accessible. Raise the spring (S)
and push one pin out. Push one end of the piston
valve out the top of the valve body (103) and the
other end out the bottom. Do not permanently distort
the springs (S).
5. Inspect the piston and seals. If damaged, replace
the piston valve assembly (119). The open seal lip
must face to the center.
6. Carefully remove the sleeves (109). Inspect the
seals (109a) and the inside surface of the sleeves
and housing (103) for wear or damage.
7. Remove the carriage (108) and carriage detent
(107).
8. Remove the screws (123), retainers (117), valve
plate (105), and seal (104).
9. Inspect the ramp (107), carriage (108), plate (105),
body (103), and seal (104) for damage or cracks.
Reassemble the Air Valve
1. Install a new gasket (102†‡) between valve body
(103) and exhaust cover (101).
2. Lubricate the valve plate (105‡). Install the seal
(104†‡) and plate (105‡) in the valve body (103).
Thread the screws (123) and retainers (117) in by
hand, then evenly torque to 21-23 ft-lb (28.5-31.1
N•m). Lubricate the sealing face of the carriage
(108‡). Install the carriage and ramp (107‡).
3. Lubricate o-rings (109a) on sleeves (109‡). Install
the sleeves. Lubricate the inside surfaces.
4. Lubricate pistons and seals of piston valve assem-
bly (119) with lithium grease. Install one end of the
piston valve assembly in the valve body (103).
Rotate the piston so the pin holes are accessible.
Install the other end and secure with the pin (P) and
spring (S).
Air Valve Seal Repair Kit NXT135 is available.
Parts included in the kit are marked with a symbol
(†). Kits include the latest part and gasket improve-
ments; use all the parts in the kit.
Air Valve Rebuild Kit NXT144 is available. Parts
included in the kit are marked with a symbol (‡).
Kits include the latest part and gasket improve-
ments; use all the parts in the kit.
F
IG
. 10. Remove Piston Stops
TI7758a
111
J
110
CAUTION
Do not permanently distort the springs. The springs
must be completely tight against the piston valve
assembly (119) to prevent interference. Ensure the
two spring wire ends are not on one side of the clip.