- 1). Park the car on a level surface and apply the parking brake.
- 2). Drain the coolant from the radiator. Place the drain pan beneath the radiator. Turn the petcock near the bottom of the radiator counterclockwise to start the draining process. Once all of the coolant from the radiator has been drained, turn the petcock clockwise to close the drain.
- 3). Remove the bolts that secure the housing of the thermostat to the water pump's feed pipe. Remove the feed pipe to expose the retaining sleeve and the thermostat.
- 4). Remove the retaining ring by prying it off with a flat-head screwdriver. Take note of the position of the notch on the retaining ring -- it must be reinstalled with the notch in the same position.
- 5). Remove the thermostat from its housing by pulling it out.
- 6). Clean the inside of the thermostat housing with a clean rag and acetone to remove any dirt or debris. Wait until the acetone dries before starting the installation.
- 7). Place the new thermostat into the thermostat housing. Insert the spring portion of the thermostat first.
- 8). Lubricate the retaining ring with coolant. The lubricant allows the ring to conform to the surface without ripping.
- 9). Install the retaining ring. Make sure the notch on the ring is in the same position as in Step 3.
- 10
Repeat Steps 1 and 2 in reverse to complete the installation.
Source...