MI-290AG
Rev. 4
6
MAINTENANCE
Removal and replacement of spray nozzles (see parts list drawing PL 290AG: p10)
Unscrew spray nozzles (20) from nozzle hub (19) and inspect for wear and plug gage. If
the nozzles need replacement, obtain new nozzles.
If a nozzle is plugged or partially plugged, clean out the orifice and inlet area with a
wooden toothpick or other relatively soft probe. Screwdrivers, wire or other hard metal items
may scratch and severely damage the orifice and should not be used.
Replace spray nozzles (20) in nozzle hub (19) by tightly screwing them in.
Removal of #46340 air motor drive (see parts list drawing PL 46340: p13)
First make sure unit is completely disconnected from air source. Using a 3/16” Allen
wrench, unscrew and remove both 1/4-20 socket head cap screws (5) and respective spring
washers (4). You should now be able to lift the air motor drive completely off the inlet body
casting, leaving the aluminum adapter (3) still attached to the 46340 air motor drive. The two
M5 socket head cap screws (1) and respective spring washers (2) can then be unscrewed and
removed using a 4 mm hex Allen wrench.
Replacement of #46340 air motor drive (see parts list drawing PL 46340: p13)
First make sure the unit is completely disconnected from air source. Next, insert the 1/4-
20 socket head cap screws (5) and spring washers (4) in the aluminum adapter (3). Align the
M5 through holes on the aluminum adapter (3) with the female threaded M5 holes on the gear
reducer (10) and secure with the 4mm Allen wrench. Attach, if not already attached, the coupler
(8) to the gear reducer (10) drive shaft and insert the coupler end of the air motor drive
assembly through the hole in the top of the 290 inlet casting. Use the 3/16” hex Allen wrench to
tighten the 1/4-20 socket head cap screws and washers in the aluminum adapter to the casting
inlet.
Note:
Air motor assemblies on older AA290A assemblies can be removed by disconnecting the
unit from the air source, then removing and unscrewing the cap screw bolts and lock washers
holding the air motor flange to the 290 inlet casting.
