But the question is why is the fluid very low. Note the reservoir gets only about half filled (there are two level lines fluid show be between). If it's much below the bottom line there is probably a leak in the system , probably from the cylinder that latches the front of top to windshield frame. Any yellow stains or rippling on your headliner?
Kompressed230xs, it is important to find the leak(s) before it destroys your headliner - hope it hasn't happened already! True, usually the front lock cylinder is the first one to leak because it gets exposed to more heat, which accelerates the chemical decay that all the main seals in the cylinders go through.
Attached below is a drawing with the location of the five cylinders in your car. Click on the drawing, and you will get better resolution. Go to our FAQ page Welcome to Top Hydraulics, Inc.
to get a crisp image.
I found the synthetic hydraulic fluid, Pentosin CHF 11S, under $20 USD at local auto zone or advance auto, forget which, but you can check availability on their websites not all locations stocked it, funny the one across the street from the MB dealer did.
SLKSport, I have done a lot of searching to check CHF 11S' compatibility with the system, and haven't found any conclusive answers. Do you have anything you could share with us all?
Chances are that it's okay. What we are looking for in the fluid for the top, is something highly refined with fairly equal viscosity over a wide temperature range (and the thinner the fluid, the faster your top will move with the fluid going through 1.8-mm ID lines), and without damaging additives. I remember that a long time ago, some fluid was taken off the recommended list because the dye in it was chemically active. Plus, the fluid cannot have emulsifiers in it, because we want all water to stay on the bottom of the reservoir.
My recommendation is still to get FeBi 02615 (aka ZH-M), which is basically the same as MB p/n 0009899103 without the green dye. These are the two MB-approved fluids for the top.
A little shopping trick with autohausaz.com: type p/n 0009899103 into their search box, and you get FeBi 02615 for $10.23 instead of $11.48 if you type in 02615... Discount OEM Brand Name Auto Parts for European and Asian Cars
You can have the cylinder(s) replaced for core or use the ebay kit with o-rings and instructions (well worth it) I know cup seals used in the replacement cyls are more "correct" but o-rings have lasted for me and replacing the whole cylinder requires removing the hydraulic lines back to the pump since the lines are permanently attached.
Top Hydraulics indeed has a core exchange program (aka up-front shipping) for the complete set, with a $1,000 refundable core deposit. The core deposit is so high, because we got burned too many times by people sending their damaged DIY cores back, and we were stuck searching for replacements.
We also rebuild any SLK cylinder you send in (provided it hasn't been damaged in a DIY attempt) for $55/ea, plus $10 flat shipping fee. Turn around two days; we average one day.
Replacing the 1 seal was about an 8 hr job for me.
SLKSport, thank you for being honest about it. The first time I took ALL five cylinders out of an SLK, without instructions, it took me five hours to remove and install all of them. Granted, I've worked on a few cars, but the majority of the work is removing and re-installing the panels from the trunk, and that is not difficult. We are working on a very detailed set of DIY cylinder removal instructions, but meanwhile we are posting on our website what a happy customer has put together:
Folks, please do the math:
The current dealer price without tax for all five cylinders is over $2,500. The rebuild/upgrade service with a 3-year warranty is about 11% of that.
How high do you think your chances are of damaging the cylinder shaft by slipping a tool just once during the DIY seal replacement process? Let me tell you, they are huge! We get damaged cylinders in on a daily basis, and it is the worst part of my job to tell people that they need to buy new cylinders. I personally think that the chances of people scratching their cylinders during DIY seal replacement attempts are actually higher than 50%. Of course, few people will come back to this forum and report that they just made a big mistake, after so many others seemed to be successful...
SLKSport, thanks again for being honest about how much time it took to replace the one seal. We rarely have people send us only the front lock cylinder and then not come back to have the rest done. Again, most of the work lies in removing the paneling in the trunk, so you save a lot of time doing it all at once, and not risking to spill fluid all over the interior when the other cylinders fail, or if you goof during the DIY repair effort.
Lastly, it's a great feeling to pull that red switch knowing that all cylinders are fine and your pump is not going to burn out on account of running dry!
Hope this helps,
(Click on the image below to get higher resolution)