Haskel AAD-5 Instructions De Fonctionnement Et D'entretien page 5

Pilot System
1. Remove hex o-ring sealed plug.
2. Remove spring and 27375 pilot stem (figure 3).
3. Inspect pilot stem and seat for foreign material. Replace stem if shank is bent or scratched.
4. Replace stem if molded seat is damaged.
5. Reassemble in the reverse manner.
NOTE: Unless excessive leakage occurs, it is not advisable to replace the o-ring seal for the shank of the
stem. This requires disassembly of the air section. If replacement is required, care must be taken in
installing the Tru-Arc retainer concentrically as shown in figure 4. Use the 27375 pilot stem valve as a
seating tool. Place the rubber valve face against the retainer and tap the top of the valve lightly with a
light hammer to evenly bend the legs of the retainer.
Test procedure for pilot control valve:
After reassembly, if the pump will not cycle, the following test procedure will determine which of the pilot
valves is faulty.
1. Remove the 17658-2 1/8" pipe plug in upper end cap.
2. Install 0-160 psi pressure gauge.
3. Apply air pressure to the air drive inlet. Gauge will read zero pressure if lower pilot valve has not
been actuated. Gauge will read full drive pressure if upper pilot valve has not been actuated.
Correct pilot valve action will cause gauge to immediately rise or fall from zero to drive pressure.
A slow increase in gauge reading indicates leakage in lower pilot valve or 568017 o-ring on inside
end of spool or 568020 o-ring on inside end of sleeve. A slow decrease in pressure indicates
upper valve or pilot tube end seals are faulty and repair is necessary. Check also for external air
leaks at plugs.
For disassembly and repair of:
Air Drive Section and Air Piston
1. Remove (4) tie bolts. Then remove upper cap.
2. Remove air barrel and static seal o-rings.
3. Remove seal on air piston.
Pump Section and Pump Piston Repair
4. Remove (6) socket head cap screws in end cap. Then remove end cap.
5. Remove retainer ring, pin and nut on pump piston.
6. Remove pump piston spacer, piston ring and o-ring.
7. * Remove air piston and rod assembly in air drive section.
Air Driven Air Amplifiers, AAD-5 & AAD-5-C • OM-11F
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