4-20. RADIATOR AND COOLING SYSTEM - Continued
Push hoses (10) onto radiator connections. Tighten four clamps (9) firmly.
Attach hose (12) to radiator connection and tighten clamp (11) firmly.
Attach air line (6) and air line (7) to the correct port on multistat (8).
(19) Apply pipe sealant (item 22, Appendix E) to the threads of close nipple (4). Attach drain valve
(1) to radiator (5) using close nipple.
Attach hose (2) to drain valve (1) and secure using clamp.
Fill radiator with a water and antifreeze solution (see LO 5-4210-220-12).
Check for leaks and repair as required.
(23) Start APU and circulate water through winterization/engine cooling system for fifteen minutes.
Top up radiator as required. Bleed any air from the inlet connection to the winterization heater in the
(24) Install radiator cap and start main engine. Check for leaks as engine warms up. Run until at
working temperature and be sure radiator fan and shroud operate.
Check transmission hose connections for leaks. Tighten or replace as required.
(26) Stop main engine and, when cool, check radiator level. Top up as required. Check transmission
oil level and top up as required.
For radiator core leak, refer problem to Direct Support.
Radiator Pressure Cap Repair
Engine coolant can cause severe burns. Allow engine to cool before attempting to maintain
The radiator pressure cap cannot be repaired. It must be replaced. The cap can be replaced
without removing the radiator from the truck.
Remove pressure cap from radiator via hole in roof canopy.
Inspect radiator cap seating area for dirt, score marks etc.