With well over a million miles of clutch experience, I believe that clutch life is HUGELY determined by how it is used. It sounds like you are onto the most important key to it and that is preventing heat. Under any load slip the clutch with the lowest RPM and load as possible to get to a point where the clutch pedal is released, thus having solid connection as soon as possible without lugging the engine.

In more severe loading like you describe, you have to do what you have to do, but just try to produce as little heat as possible.

BTW, as far as the hydraulics go, you would be much better served to use an assistant at the pedal so you could flush a few stroke of fluid through the system.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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