Regal 53 SC Owner's Manual page 223

Other Cooling System Information
Do not use sealing additives in the cooling system. They
cause buildup in coolant low-fl ow areas, plug the radiator
and oil cooler and could damage the water pump.
Do not use any soluble oils in the cooling system since
they will corode brass and copper, damage heat transfer
surfaces along with seals and hoses.
When checking coolant a refractometer must be used. It
is a Fleetguard® part and is available through Cummins.
Do not use a fl oating ball hydrometer since it may pro-
vide inaccurate readings.
Coolant Capacity- Includes block, cylinder head, water
pump, EGR cooler, EGR plumbing
Standard Modulating Thermostat- Range
Maximum Allowed Operating Temperature
Minimum Recommended Operating Temperature
Minimum Recommended Pressure Cap
Maximum Recommended Pressure Cap
COOLING SYSTEM SPECIFICATIONS
11.5 liters (3.0 gals.)
86 to 97ºC (186 to 207ºF)
107ºC (225ºF)
71ºC (160ºF)
90 lPa (13 psi)
172 kPa (25 psi)
34
WATER QUALITY
Calcium Magnesium
(hardness)
Chloride
Sulfur
ppm=parts per million.
Chapter 5
Maximum 170 ppm as
(CaCO + MgCO
3)
3
40 ppm as (Cl)
100 ppm as (SO )
4