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Second Chance Garage

For the Classic Car
Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Classic Car
Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Classic Car Restoration Enthusiast

Second Chance Garage

HOW-TO

Overhauling the Sylphon Bellows Thermostat — Page 4

Step 7. Reassemble the bronze frame to the housing and bellows using short 1/4-20 bolts and nuts. Include all the arms and clevis pins as if it were a fully completed unit. Lightly lubricate moving pieces with white grease.

Step 8. Fill a suitable container with water and immerse the completed unit into it. We used a large coffee can for this thermostat rebuild. Heat the container and monitor both the temperature and movement of the arms (Photo 11). Record this information and make your own plot if desired. Photo 12 is a graphical record of this units operation. Adding more alcohol (say four ounces) would have lowered the temperature where the shutters would have opened sooner. Verify the thermostat closes when cooled. Suggest performing several heat/cool cycles.

Photo 11 — The thermostat unit is tested on a stove to verify its operation. You may want to include a digital thermometer and dial caliber to record the results.

Photo 11 — The thermostat unit is tested on a stove to verify its operation. You may want to include a digital thermometer and dial caliber to record the results.


Photo 12 — Graph of temperature and arm movement for this Sylphon Bellows Thermostat. The Distance parameter is the distance between the two arms.

Photo 12 — Graph of temperature and arm movement for this Sylphon Bellows Thermostat. The Distance parameter is the distance between the two arms.


Step 9. Reinsert the Sylphon Bellows Thermostat into the radiator just as it was removed. Employing the long studs (Photo 13) is quite helpful, especially if working by yourself. Photo 14 is the completed installation.

Photo 13 — Just as the thermostat was removed suggest using temporary long studs to evenly seat the unit until the unit is close enough to bolt it in place.

Photo 13 — Just as the thermostat was removed suggest using temporary long studs to evenly seat the unit until the unit is close enough to bolt it in place.


Photo 14 — The thermostat unit is reinserted into the radiator with appropriate gasket and sealer.

Photo 14 — The thermostat unit is reinserted into the radiator with appropriate gasket and sealer.


Notes

  • Clean the bronze frame, stem, arms and pins well and use small amounts of white grease on moving surfaces when reassembling.
  • Since the radiator shell had to be removed to tackle this thermostat, suggest inspecting and lubricating the shutters and their operation. The thermostat will operate better if the shutters are easy to move.