I was saved a lot of trouble by a BMW windshield washer liquid level float.

Here it goes. I have a Volvo 1982 with B21A. After half an hour of a 4 hour planned trip a serious leak developed at the seal between the head and the coolant pump. The homemade coolant low level warning light came on and saved me big trouble. I stopped to see what was going on, and then we turned around. I had to add water three times on the way back home.

A couple years ago I took Steve Ringlee’s idea seriously. He had a method on how to install a low level coolant switch in the plastic tank of a volvo 240. Since I never got around ordering the proper liquid level switch I fell on that old BMW float switch in the winshield washer tank. I drilled the 1982 coolant tank on the front wall and pluged one of the switch wires as a ground for a relay controled warning light in the instrument cluster. I used the Lambda Sond warning bulb because my car does not have the oxygen sensor and it is also easy to connect to.

Although I knew it could happen I never though that a low level warning light would be usefull in the life of this car. First time this happens to me in 50 years that I am driving.

Many thanks to Steve Ringlee or other contributors for the bright idea. It saved me all the troubles associated with engine overheating at crusing speed on a highway.

By the way, I need to do the same on my other 240.

Does anyone know of any other type liquid level switch I could use that would fit a little better and does not cost a fortune?

I would prefer something that was already used on any make 10-20 years old cars. Then I could find that at the scrap yard.

Sorry for the long post.