How to Install a 1993 190e 2.6 Thermostat

1. Drain the radiator. Place a drainage container under the drainage bolt that is located on the bottom of the radiator. Open the drainage bolt with a pair of pliers. Close the drainage bolt after the fluid has drained.
2. Locate the thermostat housing by tracing the upper radiator hose to the water pump. The hose connects to the thermostat housing that is located on the water pump.
3. Loosen the band clamp that holds the radiator hose to the thermostat housing with a Phillips screwdriver. With the clamp loosened, pull the hose off the thermostat housing.
4. Remove the bolt that holds the thermostat housing onto the water pump. Pull the thermostat housing off the water pump and discard the old O-ring.
5. Pull the old thermostat out of the water pump and place the new one into place. The ball valve on the thermostat must be in the top position.
6. Place a new O-ring around the thermostat and place the thermostat back onto the water pump. Bolt it into place.
7. Attach the upper radiator hose to the thermostat housing and secure the clamp with a screwdriver.
8. Place a funnel into the radiator-filler cap and drain the radiator fluid back into the radiator.