Lubrication & Maint./2000 Hour/24 Month Testing Thermostats Opening Temperature 1. Remove thermostat(s). 2. Visually inspect thermostat(s) for corrosion or damage. If dual thermostats, replace as a matched set as necessary. CAUTION: DO NOT allow thermostat or thermometer to rest against the side or bottom of container when heating water. Either may rupture if overheated. 3. Suspend thermostat and a thermometer in a container of water. RG5971 –UN–23NOV97 4. Stir the water as it heats. Observe opening action of thermostat and compare temperatures with the specification given in chart below. NOTE:
Due to varying tolerances of different suppliers, initial opening and full open temperatures may vary slightly from specified temperatures.
Testing Thermostat Opening Temperature THERMOSTAT TEST SPECIFICATIONS Rating Initial Opening (Range) Full Open (Nominal) 71 ° C (160 ° F) 69—72 ° C (156—162 ° F) 84 ° C (182 ° F) 77 ° C (170 ° F) 74—78 ° C (166—172 ° F) 89 ° C (192 ° F) 82 ° C (180 ° F) 80—84 ° C (175—182 ° F) 94 ° C (202 ° F) 89 ° C (192 ° F) 86—90 ° C (187—194 ° F) 101 ° C (214 ° F) 90 ° C (195 ° F) 89—93 ° C (192—199 ° F) 103 ° C (218 ° F) 92 ° C (197 ° F) 89—93 ° C (193—200 ° F) 105 ° C (221 ° F) 96 ° C (205 ° F) 94—97 ° C (201—207 ° F) 100 ° C (213 ° F) 99 ° C (210 ° F) 96—100 ° C (205—212 ° F) 111 ° C (232 ° F) 5. Remove thermostat and observe its closing action as it cools.
In ambient air the thermostat should close completely. Closing action should be smooth and slow. 6. Replace any defective thermostat. On a dual thermostat engine, replace both thermostats. Continued on next page DPSG,RG34710,112 –19–23NOV01–3/5 35-7 021604 PN=165