I had the same problem......they all eventually do.
Most likely the pump is just perfect, it's the cylinders that will sooner or later leak. I think they're eight of them.
A very complicated design.
So, if one goes leaking (it will show where yours did)the others are pretty sure to follow....my recommendation is to have them all removed, rebuilt, and reinstalled at the same time.
My local MB dealership wanted close to $10,000.00 for the comlete job.
Ridiculous.
Do a search and find Dennis...Ficken? Forgot his last name. He operates a shop in Kansas rebuilding Mercedes convertible top cylinders. Very inexpensive (about $$40.00@) and with a very quick turnaround.
I had a specialist MB indie who has done the job before (Downingtown, Pa) remove the cylinders, send them to Dennis for rebuilding, then put the whole thing back together again.
It was a top-off job, and came out to $1,300.00.
Top now works flawlessly, and much faster than it did originally.
For me? No way a DIY. For you? Maybe you got skills.
Good luck with your repairs,
David

 

Find old post by forum member Kestas. He's the one that's lead everyone to the proper sources to correct cab. top problems.

Good Luck,

Jayare

 

All you need to know to DIY is in the following thread and its links:

http://www.benzworld.org/forums/w12.../forums/w124-e-ce-d-td-class/1395095-w124-soft-top-manual-operation-1994-a.html

 

Fixed my soft top

Just for you to know guys. I fixed my soft top that had exactly the same problem by rebuilding the hydraulic cylinders by myself. I now have seals custom manufactured by a couple of guys in Europe at a military factory. The seals work perfect for me. And I did not have to machine the cylinders to accept a non standard seal size or send them to somebody who can do that. I have an illustrated tutorial how to rebuild the rear lock cylinder if you have 2 minutes No kidding here! It takes 10 min to get the cylinder out, 2 min to rebuild and 5 min to put it back! Than the whole day to clean the linings in the soft top compartment which is soaked in hydraulic oil! Yours is soaked too That is why you have the oil puddle in front of the rear wheel. MB made drains there specifically for that purpose!!! Contact me if you are interested in seals. You can get them in few days. I have the seals for your both locks (rear soft top bow and the cover, just behind of the rear seat) on hands. Alternatively, you can send your cylinders to me for rebuilding (no machining, promise but I'd suggest not waste your and my time. But you have to have a small flat screwdriver to rebuild the cylinder That is it!