Howto: Cabriolet convertible top hydraulic system
Thanks for the write up on this repair. I just bought my 2002 CLK-55 AMG a couple of weeks ago and have found a couple of problems with it. One being the same problem as you have described above, leaking fluid from the lid that covers the top when closed. I had a cylinder that was leaking fluid. I followed your instructions (which was spot on) and the job went pretty smoothly. Added a little fluid and everything works great.
I have been on this site for a year or so (just have not replied any) and it has been VERY HELPFUL for other repairs that I have had for my 2000 S500.
So thanks again.
Wayne
Thank you for your post. Thankfully in my case there was no leak of fluid but my top did stop working. It worked maybe three times intermittently and then stopped working altogether.
I had to follow your instructions to get to the pump assembly because it turns out that the relay switch was not working. The relay switch is located right next to the pump assembly. I replaced it with the one off the fuel pump - same part no. - and now both seem to be working just fine.
BTW, I went to the stealership and they told me "oh no it cannot possibly be the relay, you need to bring it in for a diag." Nahh, both the fact that even I could fix it and the fact that MB incredibly smart engineers conveniently 'forgot' to build an access panel in the metal partition tells me that the stealership's name is well deserved. It is a makes-job program subsidized by those that are too lazy or scared to put their hands into their own cars.
I cannot thank you enough. I would not have undertaken this unless I had read your post.
Total cost: 3.5 hours, $0, and priceless satisfaction!
Thank you in advance,
Bill
The OEM seals in all cylinders decay with time, and the chemical reaction is accelerated with temperature. This is common to almost all modern convertibles, and you might regard the cost of upgrading your cylinders as cost of ownership for a fancy convertible. We are proud of the solution we have found to upgrade all your cylinders at a fraction of the replacement cost with inferior OEM parts. To my knowledge, Top Hydraulics is the only vendor who is able to upgrade the five black cylinders - we actually upgrade both seal material and seal type on these!
We have an up-front shipping or core exchange option, and we can usually ship the two locking cylinders mounted inside of replacement latches at no additional charge (requires a deposit, though). This saves you time, and we get the assurance that the cylinders haven't been mechanically damaged upon removal from the lock.
A few comments to enhance this thread:
- The W208 CLK Class Convertibles have seven hydraulic actuators in the top system, not counting the roll bar cylinders.
- The first ones to fail are the two aluminum cylinders borrowed from the R129 SL-Series: the Rear Bow Lock Cylinder (as described in the first post), and the Case Cover Lock Cylinder. These cylinders typically fail at about the same time, since they are using almost identical seals.
- Do not let your hydraulic pump run dry - Mercedes does not manufacture these any more, and pump rebuilds are expensive (we currently charge a maximum of $600 per CLK pump depending on the kind of damage, and MB charges close to $2,000 for a rebuilt pump)!
- If the seals are allowed to crumble apart, the particles may block the valves in your pump.
- There are only two fluids officially recommended for your hydraulic top system: the OEM fluid from the dealer, or FeBi 02615. The latter can be purchased online at currently about $11/quart. For example, go to www.autohausaz.com and type "02615" into the search box. FeBi 02615 will come up as power steering and hydraulic fluid.
- Do not use "stop-leak" type products: they make the seals swell up at first, which may or may not help, but eventually the seals fall apart and you are more likely to have catastrophic results on account of massive seal failure and potential damage to the pump assembly. OEM fluid and FeBi 02615 do not have damaging additives, and they do not suspend water in the hydraulic fluid.
Attached below please find a picture of all seven cylinders used in your system, plus a schematic showing the location of all hydraulic cylinders in your W208 CLKs. A crisp version of the schematic can be seen at http://www.tophydraulicsinc.com/diagrams/CLKdiagram.jpg.
Hope this helps,
-Klaus
klaus@tophydraulicsinc.com
Bringing the top down is my problem. It can take 3 - 4 mins, if it even goes down. Even the trunk piece closing after the top is alway the way down can take forever.
I can check and make sure it has fluids but considering the truck is slow as well, not sure where to look.
Like i said, going up, its not a problem.
Thanks
The Best of Mercedes & AMG
Bringing the top down is my problem. It can take 3 - 4 mins, if it even goes down. Even the trunk piece closing after the top is alway the way down can take forever.
I can check and make sure it has fluids but considering the truck is slow as well, not sure where to look.
Like i said, going up, its not a problem.
Thanks
welcome to the forum, and congrats on your purchase! Whatever the problem is, we can likely fix it without you having to spend a fortune on new parts. Let's try to get to the bottom of this together.
Warning: DO NOT run the pump for several minutes, or you risk burning out the motor. That would be the worst possible case, with Mercedes not making these pumps any more, and Top Hydraulics charging $600 for a pump rebuild.
We need to start out with you checking the hydraulic fluid level. That takes some time, but it's not very difficult. After removing the front panel in your trunk, you need to unscrew a lot of hex bolts to remove the cover for the pump, located in the middle of the trunk wall. Once the cover is removed, you will see the pump with the reservoir. I'm attaching a photo below.
Klaus
klaus@tophydraulicsinc.com
www.tophydraulicsinc.com
I have not had the chance to take a look yet but plan on it this week.
I am going to check on the fluids but also look at 2 wires, release wires i believe?
I read up on those on another forum and it mentioned those can cause my problem as well as the top slamming down on the front of the car when putting it up, which my top is doing as well.
welcome to the forum, and congrats on your purchase! Whatever the problem is, we can likely fix it without you having to spend a fortune on new parts. Let's try to get to the bottom of this together.
Warning: DO NOT run the pump for several minutes, or you risk burning out the motor. That would be the worst possible case, with Mercedes not making these pumps any more, and Top Hydraulics charging $600 for a pump rebuild.
We need to start out with you checking the hydraulic fluid level. That takes some time, but it's not very difficult. After removing the front panel in your trunk, you need to unscrew a lot of hex bolts to remove the cover for the pump, located in the middle of the trunk wall. Once the cover is removed, you will see the pump with the reservoir. I'm attaching a photo below.
Klaus
klaus@tophydraulicsinc.com
www.tophydraulicsinc.com
The car is in the shop right now getting the top looked at. The previous owner is paying for it.
What i know so far is the tension cables need to be replaced. I am going to do that. They said the whole top needs to be taken off and it would take 5 to 6 hours...... I found instructions here on how to do it in 30.
They are replacing a switch or something. I pick it up today and will find out what they did replace. The previous owner is paying for this part.
I also asked them to check the fluid level but not sure if they did or not, they told me it's a pain but once again, thanks to here, I can do that.
The OP is my exact problem. We have the part on order and I'm looking forward to swapping it out and getting my top working again.
Side note: if your top is having electrical problems, I fixed mine by putting something behind the luggage roller that caused it to reengage the little relay arm.
Also, if you're leaking and have the opportunity, cover your top while it's stowed with plastic or something. I leaked oil on my top.

Some of you are mentioning switching your pump to manual mode. How is this done???
And my drywall 't' square bent with a screwdriver duct taped to the end thru the hole. Where is this green button????
Last edited by Zundfolge; Oct 22, 2014 at 12:28 AM.
Don't. No reason to.
Use PB Blaster in the lock, and around the lock. Use your key and gain leverage from something like an adjustable wrench. Work it back and forth and it will go. The trunk will open this way even if the top is partially open. Be careful because your cover WILL contact the trunk if your trunk isn't all the way closed.
Once you put your top away, you can open and lock your trunk normally.
Thank you for your help. I will update after I swap out that part with the leak.
NOW, I have another problem: it stops when the top is about 1/4 the way back down. Any idea why this happens?
Top goes up perfectly.
Last edited by Zundfolge; Jun 19, 2012 at 03:37 AM.
RVC (Rollover Bar - Roof control System)
01 > B1650-001 : The positions of the limit switches do not correspond to the function sequence or are unknown. The status of a limit switch is not plausible. What does this code mean?
My car is 2001, but only has 41K miles.
Thanks for your help, Taz
Last edited by TazCLK; Sep 7, 2012 at 08:23 AM. Reason: Update. Turns out it was broken tensioning cable
I know my problem was not like others on the forums for two reasons.
1. Can't be hydraulic related; not leaking fluid.
2. Can't be relay; can hear the hydraulics being actuated when pressing the roll bar button.
Therefore, I took out the rear seat cushion and back rest. The back rest is four bolts on the bottom and two screws behind the center armrest backing. Then its a gentle tug hear and there. I found the metal cup and washer under the seat cushion. Therefore, if you haven't figured out your reason why the roll bar won't redeploy, just lift up the seat cushion and see if you have parts underneath. They may be wedged behind the back cushion too.
You will need a special two-point bit (I don't know what its called) to re-tighten the cup bolt. Use loc-tite before you re-tighten so it does not come off again.
I have attached photos to help anyone who is looking to make this fix themselves.
SirSwift93
Last edited by sirswift93; Sep 23, 2012 at 04:13 AM. Reason: Add photos.




Here is a picture of the relay. This is Palm Tree Mechanic's picture and I just outlined the relay in green.
Do you know which cylinder it might be
the most likely candidates are the rear bow lock cylinder (inside the trunk, forward of the trunk lid) or the case cover lock cylinder. In warm climates, they can have a service life of less than ten years.
Please take a look at the following DIY instructions - they show you how to get at these two cylinders, how to check the fluid level in the pump, and how to replace the fluid. The instructions were created by BenzWorld member 'joetwa', who did and outstanding job!
http://www.tophydraulicsinc.com/W208...eplacement.pdf
Within the DIY, there is also a diagram showing you the location of all cylinders and the pump. You can also find that diagram at http://www.tophydraulicsinc.com/diagrams/CLKdiagram.jpg.
Hope this helps, and please keep us posted,
Klaus
www.tophydraulicsinc.com





the most likely candidates are the rear bow lock cylinder (inside the trunk, forward of the trunk lid) or the case cover lock cylinder. In warm climates, they can have a service life of less than ten years.
Please take a look at the following DIY instructions - they show you how to get at these two cylinders, how to check the fluid level in the pump, and how to replace the fluid. The instructions were created by BenzWorld member 'joetwa', who did and outstanding job!
http://www.tophydraulicsinc.com/W208...eplacement.pdf
Within the DIY, there is also a diagram showing you the location of all cylinders and the pump. You can also find that diagram at http://www.tophydraulicsinc.com/diagrams/CLKdiagram.jpg.
Hope this helps, and please keep us posted,
Klaus
www.tophydraulicsinc.com
Thanks In Abvance!
Thanks to TopHydraulicsinc.com for great service.
One item to add.
To manually release the back window from the cover:
Open trunk - tool kit should contain an allen key
expose hydraulic lock cover (partially remove carpet cover)
Allen key fits into bolt - 1/4 turn to release back window.






