Carrier X4 7300 Operation & Service Manual page 132

00012 HIGH COOLANT TEMPERATURE - CONTINUED
6. Check Engine Cooling System
a. Compare actual engine temperature to the Unit Data reading. Temperature must be within ± 20°F (±
11.1°C).
b. Test operation of thermostat. Must operate correctly.
c. Check water pump operation. Verify no seepage at weep hole, bearings tight and quiet, and Impel-
ler firmly attached to shaft.
d. Check cooling system for scale, sludge, rust, etc. Coolant must be clean & clear with no foreign par-
ticles or substances in it. Flush & clean the coolant system as necessary.
e. Check water pump bypass hose to thermostat housing for internal blockage. Must be clear and
open.
62-11637 7–6