HALL Technical Services, LLC
T B - M A X 9 T O W B A R M A N U A L
Page 7
4. Preventive Maintenance
NOTE: Hall Industries recommends using this maintenance procedure monthly (or as required by
airlines maintenance procedures). Replace worn or damaged parts as needed.
4.1.
Replace Shear Pin. Shear pin should have a slight vertical play, spin freely and the nut
should not be tight to the head. A very small gap (0.001"-0.020" feeler gage) between the
nut and the head is required.
4.2.
Check Pivot Bolt. Verify nut is present and tightened to contact.
4.3.
Check Shear Pin Bushings. They should not be worn, cracked, or otherwise damaged.
NOTE: Always replace bushings as a set. Never replace only one bushing.
4.4.
Check adapter/tube flange bolts for tightness. Torque to 80 lb-ft.
4.5.
Check wheels and wheel carriage assembly for bent, broken, or worn parts. Lubricate pivot
points using dry lubricant (
WD-40 Dry Lubricant or Similar
). Inspect hydraulic fittings for
leaks. With hydraulic lift in the down / collapsed position Inspect hydraulic fluid for
level and quality. Add hydraulic fluid if necessary. Use hydraulic fluid per MIL-
PRF-5606H.
4.6.
Check head assembly for operation of lock mechanism. Verify that all bolts and Nord-Lock
washers are present and fully torqued (33 lb-ft). Bolts are located underneath the head.
4.7.
Inspect jaw for excessive wear or cracking. Replace head if cracked.
4.8.
Verify operation of auto safety latch and repair or replace components as required.
4.9.
Check tow eye and hardware for condition. Check that all hardware is tight. Verify that
tow eye rotates a little bit in each direction and then hits a stop.
4.10.
Check main body tube for bending or cracking.
4.11.
If the drag plate is worn and towbar head or eye is dragging use replacement drag plate
kit.
4.12.
Clean, repaint or touch-up paint as required.
4.13.
Inspect tags and labels. Replace if damaged or missing (see the drawings in the
attachment section for labels and placements).
