Could not hear or locate any vacuum leaks. The heat still has a mind of its own, and turns on even though the dial is set to cold. I believe it to be a vacuum problem because as soon as the car is up to highway speeds, the heat turns off. Apparently, it is taking time to build up enough vacuum.

Any other suggestions? Alternatively, is there a way to simply disconnect the heater for the summer? At Mercedes-Benz labor rates here in England at $200 per hour, I would like to resolve this problem myself.


In advance, thank you.

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1998 W210 E300TD
1997 W202 C230
1990 W124 300TE
1985 W123 280TE (sold)
1983 W123 300D (sold)
1981 W123 240D (sold)
1980 W116 280SE (sold)
1980 R129 450 SLC 5.0 (sold)
1975 W115 240D (sold)