IH cleaning solutions are available which have proven very successful in removing accumulation of rust, scale,
sludge and grease. This solution should be used according to the recommendation on the container.
IMPORTANT Do not use chemical mixtures to stop radiator leaks except in an emergency. Never
use such solutions instead of needed radiator repair. Do not use soluble oil.
When draining the cooling solution, disconnect the radiator outlet hose, as large particle of sediment will not pass
through the drain.
3-9.2.4 Radiator and Condenser Fins. Check the radiator and condenser fins periodically to make sure they are free of
bugs, leaves and other debris, and that they are not bent or damaged. Clogged or damaged fins prohibit the flow of
outside air to the radiator and hamper efficient cooling system operation. Use a fin comb to clean and straighten fins.
3-9.2.5 Coolant Hoses. The only coolants which are recommended for use in Navistar Truck cooling systems are those
which contain an ethylene glycol base. Other base coolants may damage rubber hoses, especially those made of silicone
rubber. Type of rubber can usually be determined by color. Silicone hoses are made in COLOR while other rubber hoses
are BLACK. If coolants are not of ethylene glycol base, this may affect your engine warranty.
Your new truck is equipped at the factory with a high temperature (1800) thermostat.
Permanent type anti-freeze must be used with high temperature thermostats.
3-9.3 Fan and Accessory Drive Belts
Replace belt(s) if worn, cracked or grease and oil soaked. Replace worn pulleys.
New belts have a break-in period and lose tension during groove seating.
IMPORTANT New belt initial installation tension is higher than the re-tension value applied to a used
belt (run five minutes or longer). This is done to minimize number of belt adjustments and prevent belt
operation under low tension during break-in period.
Belt tension checks should be performed using a Belt Tension Gauge.
New belts should be checked at 300 miles (483 km) or 10 hours, then checked again after 1,500 miles (2 414 km)
or 50 hours. The second service adjustment of belts establishes tension stabilizaiton.