Help,just bought a 1998 slk and having trouble getting the top to go down.the light flashes fast when I try to get it to go down and I have checked all the fuses.could this be the controller or the hydraulic lifts. I do hear the noise coming from the back when I hit the button.please help. I really need to know.

 

did u check the hydraulic fluid level in the pump? it's in right trunk side panel. it should be between the two triangles. do the windows come down when you pull back on switch?

 

after further thought. the right and left hardtop locked limit switches are a common problem for this issue. remove dome light cover to access screws and remove visors and pull straight back on the cover, not down, it has push on clips. there is another switch where the roof aligning pin goes in on the passenger side that tells the control unit that the top is closed. that is a different issue and not this problem, it's the other two that are the most likely culprits

 

brookings...just read your post - I have a little different problem (above) same year '98....my pump is completely dry and the top does not move.

I was able to put it up manually with the allen wrench.

What type of fluid is used and is there a filling procedure any where?

 

get a flashlight and look under all the lines coming into the pump. there is an allen screw on top of the pump on the back side of the lines. fill there. you'll need a funnel with a flex-line to fill with fluid part #000 989 91 03 10. then you'll need to figure out where the old fluid leaked out. you can easily see two of the cylinders in the front of the trunk on either side. get a small mirror to check the one on the fender side of the pump. check for oil leaks or spots around the bottom of the left rear wheel fender well. check for leaks around the top of windshield pillars.

 

Well OK then....is there another product available other than going to the MB stealer?

Has anyone ever tried hydraulic jack oil - very thin. There is also several stop leak products that work to "re-energize" the seals and stop or slow down leaking seals. Several of these are decent products - I used one in a floor jack that was leaking and I was pleasantly surprised with the results. It stopped leaking completely, is still good over a year later.

I think it would depend on whether this oil is the same chemical makeup a jack oil....

 

go to mercedespartscenter.com and type in the part #I gave. it's only $12 plus shipping. When in doubt, ALWAYS USE OEM

 

Well I am going to try BarsLeak's Hydraulic Stopleak - I went to there website and posed the mix question to them and they said that it had been tested with all types of hydraulic and mineral oil as well as the current synthetics. They said there had been no compatibility problems what so ever.

I don't see where I can cause a problem - if it doesn't work, just replace the cylinder after flushing the stop leak out. They said it definitely will not cause any clogging problems so it should not be a problem other, than maybe not working/softening against the seals in question.

Nothing to lose and everything to gain.

 

I agree with forcedinduction and don't use stop leak in your cooling system either. fix the problem.

 

Coming from the BMW world - I would say you speak like a true MB purist......

The system is just a mineral oil hydraulic system - a pump with ram jscks. There is nothing special about it except the poor quality from MB. Why do we always think that because the Germans made it it has to be "special". I agree they do make some very well engineered products, including their cars. They also make some inferior products as well - like their plastic cooling parts, their older AC systems and a lot of their hydraulic systems must be added. I say this because of my experience with BMW power steering, cooling systems and now the MB top mechanisms - they all seem to leak!!!

I would not use most stop leak products in cooling systems but I have used Bars products in an emergency - never had a problem. I also used their hydraulic stop leak in a new floor jack. I bought the jack, left it in the box for 18 months while moving, when I unpacked and put it into service it immediately started to leak. I was upset but not having recourse I decided to try the Bars' stop leak product. It has now been over 6 months, the leak has stopped and I have no problems. It does not work on a principle of "plugging" the leak, it simply conditions the old seals that may have become hard, brittle or otherwise causing the leak to occur. If the seal does not respond, it does cannot help the problem and you simply have to replace the seal go forward.