Page 10
HENDRICKSON NHT SERIES
1.1.1.3 MECHANICAL
SPRING
HUTCH 9700 SERIES
1.1.2
AIR SPRING SUSPENSION INFORMATION
Regular preventive maintenance checks on air spring suspensions are the same as on leaf spring
suspensions with the addition of the air bags and air components. With the air pressure above 65
psi, the height between axle and frame should be within 1/4” of the same height at all air bags. If
not, it may be an indication of air loss at one or more air bags, air leaks at fittings, or malfunctioning
leveling valves. Leveling valves should have proper clearance to permit leveling arm to actuate
freely and not be bent or twisted. Do not grease leveling valves. There is a time delay of 2 to 6
seconds before the leveling valve will add or exhaust air to the air springs. The proper position of
the valve actuating lever is in the center or neutral. Lever up will add air; lever down will exhaust air.
Check leveling valve lever for being in proper position while trailer is connected to tractor in drive
away condition.
In the event of failure in one or more air springs, it is recommended the height control valve linkage
LINK TO VENDOR FILE
LINK TO VENDOR FILE
