Cabrio Hydraulic Pump

[tac27]

I found and followed the post in the DIY section to fill the cabrio top pump with pentosin.

I ran into something interesting in that my pump looks nothing like the pictures from the DIY post. I purchased the Bentley manual and I have the service manuals I purchased from Porsche Librarian; neither of those show the pump I have.

As you can see from the pictures, my pump is rotated 90 degrees clockwise, with the resevoir tank pointing at the nine o'clock position. I included one picture from the DIY article that shows the pump and tank in the 12 to 6 position.

The lines also attach at different points and there is no filler hole on the face; that one plug you see does not lead to the tank. Instead, there is a plug on the end of the tank-you can see it the pictures.

There is a plus sign (+) on the front side of the tank, so I decided that was the fill level...

To fill it I detached the whole assembly from the alluminum roll bar frame. If you look closely at the pictures you can see that there are four threaded studs that are welded to the frame; the nuts are 10 mm and the lower left nut is missing! I first had to detach all the wiring that leads into what I think is the engine control panel.

There is enough play in the lines and wiring that I could tilt the tank upward, remove the plug at the end of the tank, and add the pentosin. I used a kitchen baster (note: never use your wife's expensive William Sonoma baster/injector....) and filled the tank to the top arm of the plus sign.

I tested four open to close cycles and the top seems to be working very well now.

So has anyone seen this alternate configuration for a cabrio hydraulic pump? Anyone have information on how it should 'officially' be done?

Thanks,

Tim

Las Vegas, NV

2003 996 C2 cabriolet with just over 152k miles.

[Loren]

The hydraulic pump changed in 2002 (and again in 2004). I think all the DIY photos here are MY01 and older.

Here is the procedure (from the service manual) for MY02 and newer.

(click to enlarge)