Landoll 440B Series, Operator'S Manual, Page: 33 / 84

OPERATING INSTRUCTIONS
3-21
TABLE OF CONTENTS
Air Ride Operation
1. Trailer air pressure must be maintained above 90 PSI
before operating. PROTECTION VALVES are used to
maintain 65 PSI air brake pressure during
suspension or remote system air loss.
2. The Model 440B tandem axle semitrailer is equipped
with a ride control valve located on front axle. When
moving the undercarriage from transport to load
position, the front axle is raised off ground, causing
suspension air bags to deflate achieving low load
angle.

CAUTION
3. The Model 455B triple axle semitrailer, with 10’-1”
spread between front and rear axles is equipped with
additional height control valves to adjust the
suspension during loading and unloading operations.
When moving the undercarriage from transport to
load position, the undercarriage is tilted with the
center axle air bags inflated and rear axle
suspension air bags deflated to achieve low load
angle. This function positions the center axle for
added undercarriage support to the semitrailer and
payload when tilted for loading/unloading.

CAUTION
4. Different tractor fifth wheel heights may affect proper
operation of the triple axle suspension air system. In
the event front and rear axle suspension air bags are
not inflated or feel soft by the time the undercarriage
has reached transport position, adjustment to the
front and rear axle control valve linkage may be
required
(See “Triple Axle Air Ride Height
Adjustment for Transport” on page 4-10 .)
Bulkhead (Option)
Optional bulkheads may come with or without chain
racks. To remove a bulkhead, disconnect the electrical
harness (if work lights are present), remove retaining
pins holding the bulkhead into the pockets on the
semitrailer front and bolts and nuts attaching the
bulkhead extensions and supports to the deck, and lift
the bulkhead off
( See Figure 3-13 .)

DANGER
If suspension air loss should occur, completely
deflate suspension and temporarily operate on
the air springs internal rubber bumpers. Carefully
proceed to the nearest semitrailer service facility.
To deflate the air suspension, disconnect the
lower connection on the linkage of the automatic
air valves. Rotate the valve control arms down
about 45
o
to exhaust the air. To restore to normal
operation, simply reverse the procedure.
Insure suspension air bags are inflated on all
axles when moving undercarriage from load to
transport position. Failure to do so can cause
excessive tire wear.
To avoid serious injury, all removable
attachments must be firmly attached with
fasteners provided at all times.