Dismantling and checking the thermostat

Remove the thermostat only when the engine is cold. An experienced amateur will be able to do this work, but in the workshop they will do it better. Just in case you feel up to it, first relieve the working pressure in the cooling system and put the necessary spare parts ready. You need a thermostat, a thermostat housing cover gasket, and a permanently flexible heat-resistant sealant (e.g. DP 300 from Wiirtli). Thoroughly update the sealing - the cooling system is constantly under pressure. Collect the escaping coolant in a clean container; after repair, you can use it again without hesitation. However, if you want to test the functionality of an old thermostat, heat water in an unused saucepan and check the temperature of the water with a canning thermometer. On the thermostat housing you can read the regulation temperature and compare it with the water temperature. However, we do not advise you to rely on an unkempt thermostat.

Stages of work

Open the cap on the expansion tank to relieve the pressure in the cooling system. Be careful if the engine is hot: danger of scalding

Place a clean receiving container under the radiator, remove the lower radiator hose or unscrew the drain plug. Drain approximately three liters of coolant.

Loosen the hose clamp on the thermostat housing and remove the coolant hose.

Loosen the fixing bolts of the thermostat housing, carefully remove the housing, if necessary, help yourself a little with light blows (rubber or plastic mallet) along the hull.



Thoroughly clean the sealing surfaces, put the thermostat into the housing (the arrow on the case points in the direction of the radiator), lubricate the new gasket on both sides with a thin layer of sealing agent (e.g. DP 300) and fix on the flange.

Carefully place the housing cover on top, apply a small amount of sealant between the cover and the threads, install and tighten the bolts evenly.

Attach the coolant hose, pour in the drained coolant, add if necessary.

Warm up the engine at medium speed, constantly check all mounting points for leaks. Close expansion tank.