TM 9-2330-294-14
Table 4-4. Troubleshooting Air System Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3 2 . AIR SPRINGS INFLATE NORMALLY IN ONE POSITION OF AIR CONTROL
VALVE HANDLE, BUT NOT IN OTHER TWO.
Step 1. Check for defective two-way check valve (para 4-37k ).
Replace valve (para 4-51).
Step 2. Check to see if air control handle is secured to valve.
Replace valve if handle cannot be secured (para 4-48).
Step 3. Check for defective or misadjusted pressure regulator valves (para 4-37i ).
Adjust valve(s) (para 4-37i ) or replace valve(s) (para 4-49).
Step 4. Visually inspect air lines supplying air to regulator valves for dents or breaks. Cautiously
loosen fitting on line suspected of being plugged and listen for escaping air while air
control valve handle is in appropriate position. No air escaping indicates plugged
line.
Replace damaged or plugged air line (para 4-39).
Section V. TROUBLESHOOTING
4-13. Scope
4-14. Troubleshooting Table
a. This section contains troubleshooting in-
The tests and corrective actions provided in tables 4-
formation for locating and correcting most of the
3 and 4-4 are" governed by scope scope of the
operating troubles which may develop in the
organizational level of maintenance. Table 4-3 in-
semitrailer. Each malfunction for an individual
cludes a list of malfunctions, tests or inspections and
component, unit, or system is followed by a list of
corrective actions for the semitrailer electrical
tests or inspections which will help you to determine
system, suspension system and frame assembly.
probable causes and corrective actions to take. You
should perform the tests/inspections and corrective
inspections and corrective actions for the brake and
actions in the order listed.
suspension air system. Procedures and tests used in
b. This manual cannot list all malfunctions that
conjunction with troubleshooting the air system are
may occur, nor all tests or inspections and corrective
included in paragraph 4-37.
actions. If a malfunction is not listed or is not
NOTE
corrected by listed corrective actions, notify your
Before you use these tables, be sure you have
supervisor.
performed all applicable operating checks.
Section VI. ELECTRICAL SYSTEM MAINTENANCE
(c ) Unshort the meter leads and check for
shooting
continuity between pins D and L on trailer receptacle
(J 1, fig. 4-4 or 4-5). Full deflection on the ohmmeter
should occur (zero ohms). If full deflection does not
4.5).
occur, check each pin to ground to determine which
(1) If light circuit is inoperative, insure bulbs
pin is not grounded properly. Repair faulty circuit.
are good before proceeding with open circuit test.
(d ) If pins D and L of trailer receptacle J1
Repair obvious breaks in wiring at harness ends that
are properly grounded, locate the pin on the trailer
are accessible (para 4-28c ).
receptacle for the failed circuit.
(2) If no break is visible, use volt-ohmmeter
(e ) On the trailer receptacle, J1, connect a
and check for open circuit as follows:
jumper wire from the pin of the failed circuit to pin D
(a ) Place the range selector on the meter in
or L.
the Rx100 position.
(f ) Place the range selector on the volt-
(b ) Perform steps b (4) (b ) through (d ) of
ommeter in the Rx100 scale position.
Short Circuit Test below.
