4-15. AIR SYSTEM TROUBLESHOOTING PROCEDURES (CONT).
4. DRAWBAR WILL NOT RAISE OR REMAIN RAISED.
Tools and Special Tools
Tool Kit, General Mechanic's: Automotive
(Item 50, Appendix J)
Pressure Test Kit (Item 34, Appendix J)
Engine OFF, (TM 9-2320-364-10)
Parking brake applied, (TM 9-2320-364-10)
Wheels chocked, (TM 9-2320-364-10)
Solution, Soap (Item 21, Appendix E)
Charging hose connected to trailer
quick disconnect and truck, (Para 2-9)
Trailer air system charged, (Para 2-22)
Soap and water solution will be used to visually check for leaks.
There are two models of drawbar assist control valves. Model B replaced Model A.
Model A has air lines on top of valve and uses elbow and reducer fittings.
Model B has air lines on back of valve and uses straight adapter fittings.
Truck air system OK.
Is drawbar free of damage or
REASON FOR QUESTION
Drawbar frame faulty.
If drawbar binds or is damaged,
Air lines and fittings faulty.
drawbar will not raise.
Quick disconnect check
Air reservoir 1 check
Air bag control valve faulty.
Inversion valve faulty.
Safety valve faulty.