Vae Victus
Posting more than I know
Since it has been nine years since a thread has been created discussing the installation of a thermostat on a 2F engine, and since I spent about 30 minutes yesterday trying to figure out how to do the installation correctly with the odd gaskets that are included in different rebuild kits, I thought I would quickly show the steps that one would take to properly (hopefully) install the thermostat. (Also the old thread has lost its picture links)
EDIT 8/12/19: Cool Cruisers and SOR have gaskets (upper, lower - thick and thin) readily available. Search on their sites for "thermostat gasket". Not sure (it's been a while) but there may be OEM parts available as well. Search on your favorite Toyota parts website).
1. On a cool engine, locate the thermostat. It is on the front on the straight 6 engine (F thru 3FE). In the photos below it is circled in yellow.
Place a bucket or pan underneath and loosen the hose clamps. Allow the coolant to drain into the bucket.
2. Remove the top half of the thermostat housing by removing the two bolts. Remove them slowly and carefully as these have a high tendency to break within the aluminum housing. They are fairly thin and long, and bind up in the aluminum due to the increased exposure to water.
3. Remove the old thermostat from the housing if you are going to replace it with a new one. If you are not then you should test the thermostat to make sure it still works by placing it in a pot of water and monitoring the temperature until it reaches the proper expansion temperature. At that time the thermostat should expand.
4. Remove the old gasket. Clean the lower and upper mating surfaces of any residue from the old gasket. Use a razor blade to scrape for material from the face of the thermostat housing, and then use a cleaning agent like general spirits, brake cleaner, or other non-residue creating cleaner to remove the oil from the surface.
5. Insert the thermostat with the visible spring facing down and the domed part up. It should fit into the lip in the lower housing. Install the thermostat so the "jiggle valve", as the FSM describes it, is located at the 11 to 1 o'clock position in the housing. It allows a little circulation until the thermostat opens. (NOTE: the thermostat pictured below does NOT have a jiggle valve).
This is the bottom:
This is the top:
EDIT 8/12/19: Cool Cruisers and SOR have gaskets (upper, lower - thick and thin) readily available. Search on their sites for "thermostat gasket". Not sure (it's been a while) but there may be OEM parts available as well. Search on your favorite Toyota parts website).
1. On a cool engine, locate the thermostat. It is on the front on the straight 6 engine (F thru 3FE). In the photos below it is circled in yellow.
Place a bucket or pan underneath and loosen the hose clamps. Allow the coolant to drain into the bucket.
2. Remove the top half of the thermostat housing by removing the two bolts. Remove them slowly and carefully as these have a high tendency to break within the aluminum housing. They are fairly thin and long, and bind up in the aluminum due to the increased exposure to water.
3. Remove the old thermostat from the housing if you are going to replace it with a new one. If you are not then you should test the thermostat to make sure it still works by placing it in a pot of water and monitoring the temperature until it reaches the proper expansion temperature. At that time the thermostat should expand.
4. Remove the old gasket. Clean the lower and upper mating surfaces of any residue from the old gasket. Use a razor blade to scrape for material from the face of the thermostat housing, and then use a cleaning agent like general spirits, brake cleaner, or other non-residue creating cleaner to remove the oil from the surface.
5. Insert the thermostat with the visible spring facing down and the domed part up. It should fit into the lip in the lower housing. Install the thermostat so the "jiggle valve", as the FSM describes it, is located at the 11 to 1 o'clock position in the housing. It allows a little circulation until the thermostat opens. (NOTE: the thermostat pictured below does NOT have a jiggle valve).
This is the bottom:
This is the top:
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