OPERATION OF MEDIUM WRECKER (Contd)
Install boom jack (1) in base plate (3) and secure in place with retaining pin (7) and retaining clip (8).
Obtain tie bar (2) from wrecker bed and install between boom jacks (1). Secure in place with retaining
pin (5) and retaining clip (6).
Push boom control lever (9) to DOWN position, and release it when boom jacks (1) make firm contact
Perform lifting and lowering operation. Refer to steps 10 and 11. (14) Heavy side lifts are similar to
heavy rear lifts except that front and rear outriggers (4) from the lifting side of the vehicle will be positioned.
e. Towing With Wrecker Crane.
If vehicle being towed has inoperative compressed air system, emergency air and service air lines must
not be connected between vehicles. Failure to do this may result in damage to equipment, or cause
injury or death.
If the compressed air system of the vehicle being towed has emergency air and service air lines, they
must not be connected.
Do not use towing as a means to start engine of vehicle with automatic transmission. Refer to disabled
vehicle operator's manual for towing instruction. Failure to so may will result in damage to vehicle.
Maximum towing speed shall not exceed 35 mph (56 km/h) on paved highway or 15 mph (24 km/h) on
When towing M939/A1/A2 series vehicles with inoperative compressed air system, the spring brakes
must be caged.