I found a Ponton for sale that runs well and is in good shape. The fellow reports that it goes into gear only when the engine is not running. I suspect that a vacuum leak in the Hydrak clutch is causing the trouble. Are these fixable/worth fixing or should I think about the conversion to regular clutch instead? This car is only $1500 or so. I'm thinking about it or I'll put that money towards paint on my 300E.

Thanks,

__________________
VR
1967 250SL

Even when these caes were relatively new lots of them were converted. The system had its "bugs". Neat stuff but problematic would be a compliment.
Regards,
Randy D.

Hydraks in good working order, work. However, using them is an acquired taste. Touching the gear shift lever, (engine running), activates electric sensors in the shift column. This then activates the vacuum system, (a storage tank in the left front wheel well), and engages the clutch.
The hard part in driving is going thru the gears. If the shift lever is touched while accelerating, the clutch engages, which tends to make a lot of engine noise, which causes one to let up on the accelerator followed by removing hand from gear shift, followed by car stalling. As I said, it is an acquired taste.
The fault in not working, as you described, may be in the vacuum system, or just as likely in the electrical sensors, which get dirty, out of adjustment, or even blow a fuse. First thing, check the fuse.
MB used to make a conversion kit, but I don't think they available. You might check MB vintage parts.
Good luck, Ed

You'll find a good overview description of the system in the paperback copy of the manual for "Passenger Cars Starting 1959". The one volume loose-leaf manual ommited this section (the 3 volume set has it, and in color).

If you want to keep the car "original" and it's worth doing so, keep the hydrak and be the only guy in your neighborhood to have one. Then again, if the car is a daily driver, convert it.

-CTH

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