When a fan belt breaks and a replacement is not available, mend or substitute it. To mend a broken fan belt—
- Punch holes in both ends of the broken belt and put a small gauge wire or bootlace through each hole.
- Secure the wire or laces.
- Replace the belt with just enough tension to drive the vehicle accessories.
To substitute for the broken fan belt—
- Use fiber rope from the vehicle tarpaulin or a piece of field telephone wire.
- Loop the wire or rope around the pulleys several times, pull as taut as possible, and tie with a square knot.
In both cases, operate the engine at low speed. This will prevent breakage or loss of the substitute belt.
Source: U.S. Army FM 4-30.31, Recovery and Battle Damage Assessment and Repair