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Discussion Starter #1
My 2007 SL550 has a hydraulic leak on the passenger side above the window on the hard top convertible. It leaks only after being closed. It opens and closes perfect just after it closes or during closing it leaks hydraulic fluid all over the passenger seat. I am assuming there is a leak in a line or I think there is a cylinder there that must have a o-ring or something going out.

I used to be a mechanic so I have skills but not on Mercedes or convertible tops and limited hydraulics.

Any ideas or schematics of the system would be very helpful. Even just a quick patch fix in the meantime so its atleast not leaking everytime I close it. Thought if I could just put a rag up in there for now or something? I dont even know how to open up the headliner properly to inspect anything. Thanks
 

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Discussion Starter #3
Thanks PhamB for the reply.

Only thing is that I am actually trying to sell this car ASAP as I need the extra $ and I dont have the time to do a whole new refab as well take out, send, wait and then re-install everything.

Car has 66k miles but it is in Hawaii in a very hot area so I am imagining that the heat made the seal go out early in whatever part is there.

Is there anyway I can just repair that one part that is leaking? I could still send it in but I dont even know how to get in there and take it out. Do you have any support on removing that leaking part and know what part is actually leaking above the passenger seat/window when I close the top? Thanks
 

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SL500, 2000, R129
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5 Posts
If it's the cylinder up front above the visor, you can repair it yourself pretty easily. I bought new rings on eBay and repaired one of mine.
 

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Discussion Starter #6
Thanks again for the info...

Its actually leaking on the closing sequence of the top. And its leaking right out of the opening/crack that is there where the roof is split into pieces to be able to fold up and down.

It leaks right onto the passenger seat bottom as soon as the top comes all the way down.

Is there a cylinder above the passenger seat/window? Or do I have a hose or connection leaking?

I dont think its above the windshield or the top latch leaking as its not leaking above the window just above the passenger side seat and pretty good drip as I have to put a rag on the seat to catch it all. I am no longer using the top but being in Hawaii its a shame to have a convertible and not be able to use it...

Its a 2007 SL550 with 66k miles. Your support is greatly appreciated!
 

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2006 SL600
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In addition to tophydraulics, there is another vendor cabriolethydraulics that has a patented coupler so you can replace the cylinder without pulling the entire hydraulic line out (which can be a pain for the one that’s above the headliner).

I have not used that product, but I have bought other rebuilt cylinders from Cabriolet Hydraulics and had a good experience.

They do advance replacement and provide detailed instructions on how/where to CUT the existing line. If you are comfortable removing the headliner (and don’t have reservations about cutting the hydraulic line - which can’t be undone...), it seems to be a fairly easy diy option.

I’ve also used tophydraulics and had a good experience with them as well.

Friendly reminder - if you remove the headliner yourself, make sure you put plastic over the interior (and anything under the top where you are working) so you don’t get the fluid on the leather or paint - there is definitely more fluid up there...

Hope this helps!
 

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Ahh sorry, my experience is only with the R129. Maybe owners in your year group will give you feedback.
 

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Discussion Starter #9
In addition to tophydraulics, there is another vendor cabriolethydraulics that has a patented coupler so you can replace the cylinder without pulling the entire hydraulic line out (which can be a pain for the one that’s above the headliner).

I have not used that product, but I have bought other rebuilt cylinders from Cabriolet Hydraulics and had a good experience.

They do advance replacement and provide detailed instructions on how/where to CUT the existing line. If you are comfortable removing the headliner (and don’t have reservations about cutting the hydraulic line - which can’t be undone...), it seems to be a fairly easy diy option.

I’ve also used tophydraulics and had a good experience with them as well.

Friendly reminder - if you remove the headliner yourself, make sure you put plastic over the interior (and anything under the top where you are working) so you don’t get the fluid on the leather or paint - there is definitely more fluid up there...

Hope this helps!
Thanks so much for the info...I bought a coupler to see if that will fix it as I think the line, or atleast hope, just the line is leaking above the passenger side seat up in the roof.

My only other question is how exactly do you get access to the roof hydraulics? I will be working on it this Monday so hoping for some support. Looks like you just open the top slightly to get at screws in the front and the side railing them the headliner will pop off...Do you know how to get in there or have done it? I am pretty sure I got it just could not find much or any info out there about an SL class headliner removal but I will give it a try...used to be a mechanic but not worked on Mercedes much at all and just mostly engine stuff.

Thanks!
 

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2006 SL600
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See this thread - comment #2 from @rudeney provides a link to the instructions


You mentioned that you bought only the coupler. I hope that works for you since in my experience the hydraulic cylinder is where the leak is coming from, not the line.
 

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Discussion Starter #11
I actually ended up buying a new front top cylinder...you were right it was leaking. I should have it today or tomrrow. I had a question though as
See this thread - comment #2 from @rudeney provides a link to the instructions


You mentioned that you bought only the coupler. I hope that works for you since in my experience the hydraulic cylinder is where the leak is coming from, not the line.

I actually ended up buying a new top cylinder. You were right it was leaking. Should have it today. Now I am doing the task of taking it out and tracing the hydraulic lines back to the pump. I had a couple questions for you and if I could get an answer I would be very grateful as I need to get this fixed ASAP to get it to someone.

1. You know any tricks to tracing the hydraulic line back to the pump? I got it all off under the headliner but once it snakes back towards the trunk I lose it and I cant even pull from the trunk or the headliner and get them to move to see which ones are which. Seems they are very tight in there. Was thinking to just cut the old ones and snake the new ones in myself and of course make sure they dont get pinched when the top opens or closes as I am sure that is why they are all how they are.

2. Do you know which 2 lines from the pump manifold in the trunk are the top latch cylinder? If I have to cut them I will then need to know which 2 lines to take off...that is why I was trying to trace them to the pump which I may try again.

3. Also how do you purge the air from the lines or the pump after I install the new top cylinder? Since the lines are hard wired into the cylinder I cannot just bleed them for air. Is there a bleed valve on the cylinder? Also my hydraulic pump only has one allen key port on the top. Not a fill port and a bleed port. I cant seem to find anymore ports on the pump. There is a allen screw on the edge of the plastic oil reservoir that I filled oil into with a syringe when I thought that maybe the pump was just low on oil. I will attached a picture of my pump. Its on 07 SL550. Just not sure once I hook it up how to bleed the top cylinder and whole system properly so it all works again. I got some ideas but Mercedes are not my specialty and first time working on a roof like this.

4. Also one last thing. I was trying to open the roof before I figured out the top cylinder was the culprit and it started the process slightly and ended up opening the trunk about 2 inches to accept the roof into it. Then the cylinder really started to bleed alot and I think I got alot of air in the lines. Now the trunk is popped about 2 inches in the back and I cannot close it via the hydraulic system or putting pressure on it. The trunk is closed from the back but the part by the window is popped up. I was going to try and open the valve on the pump and bleed it while pushing the trunk lid down or I guess try and trace the lines from the hydraulic piston holding the trunk open to release the pressure and hopefully it will go back down.


If you had any idea where I could find a diagram to what goes where in this hydraulic system. What each line is on the manifold and how to properly bleed the system and the pump I would be very grateful...I am even willing to pay you for you help as I really need it right now and kinda under the gun with time here. I can paypal you not a problem as I appreciate your support fully and seem like you know your stuff. Really appreciate it, heading to work on the car now. Thanks!

2640043
 

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2006 SL600
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36 Posts
#1 Tracing the lines back - I haven't done this myself, but anecdotally I've read accounts of people who have and it doesn't appear to be a simple task. The plastic tabs that hold the lines in place tend to break since they are old and fragile. The cabriolethydraulics coupler fitting that I mentioned in an earlier post on this thread is meant to save you the hassle of pulling the entire hydraulic line by splicing the new cylinder into the existing line closer to the cylinder. I'm not recommending one way or another that you do this...The existing hydraulic lines are permanently bonded to the end fitting and the cylinder and you can't "un-cut" the lines if you run into issues.

#2 which 2 lines from the pump manifold in the trunk are the top latch cylinder? Try searching this forum for a diagram. I don't have one, but I'm sure someone else does.

#3 bleeding the lines - no need to bleed the lines, the pump will cycle all the air out. The cycle will take longer and the pump will have a higher pitched sound while it's cycling the air out, but that's nothing to worry about. NOTE: after you cycle it through and the top opens (and closes), make sure to check the fluid level in the hydraulic pump reservoir - you will need to top it off since more fluid is in the lines than when you started.

#4 closing/latching the roof - Using the picture you posted, there is a hex screw on top of the pump just above the MB part sticker. Turn that counter clockwise (no more than two turns) to release the pressure in the lines. Push the top down (it should actually fall into place when the pressure is released). Sitting in the driver seat inside the car, looking toward the front edge of the headliner you will see a small plastic cap. Pry it off (it just clicks in, not threaded) to uncover a hex screw. Turn the hex screw counter-clockwise to lock the top latches - and clockwise to unlock, if you want to unlock it again for any reason. Replace the cap (you might never find a replacement if you lose it, LOL). Tighten the hex screw on the pump to "close" the system.

Hope this helps!
 

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Discussion Starter #13
Thank you very much...issue is I only got one of the parts for splicing in the lines...my mistake. So I am going to try and do it the old fashioned way. I am sure I will figure it out. All the other info is helpful. I already had the top cylinder out and headliner off and already twisted that hex on the roof to lock and unlock. Good info about the pump purging itself out...where does the air go? I dont need to open the screw just a little to bleed? I thought I already tried to open the hex on the pump and push down on the trunk before but I will try it again and I have help now. I am at the car now so we shall see. I wish the lines were numbered!

I tried searching for a thread about the lines and where each is at. could not find anything. Have you ever seen a diagram with what lines go into the manifold on the pump? My concern is if I just cut the lines and put through my own lines into the trunk I will not know what lines go to the top cylinder I am replacing...if I only had an answer or diagram to where the 2 lines that go to the top latch are at the manifold I would feel more confident. Any support with that would be immensely appreciated. I am also not so sure what to really search for and what I find is an older car or a different pump. Cant find a SL or 550 or 07 year range. Thanks!
 

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Discussion Starter #14
Tried the trunk closing...back of trunk closes but the part near the rear window is sticking up. Opened the pump to let the oil out. It came out but the trunk rises back up. Definitely does not "fall" int place. I have to sit on it to close it. It then rises back up??? Tried opening the pump completely as well just 2 turns like you said.

Also I tried manually opening the roof. It is stuck closed. The latch is manually opened but yesterday I lifted the roof no problem with just myself. Now today with 2 people I cant even get it to budge. Seems like it is locked or seized?

It may be in the early stages of opening the roof as I was trying to open it yesterday and got the trunk to open to the position it is now. Now the roof will not open and the trunk will not close. I am at a loss here on what to do?

Only thing I can think of is try and trace these lines back and replace the top latch cylinder somehow and try and get the system to work with the hydraulics again. I just dont know how I will be able to do it without opening the roof and getting into the area behind the drivers seat where I can see where the lines go down. Any help would be much appreciated as I only got one coupler so I cannot just cut into the lines which was a huge mistake and took over a week to get to me. I have to get this fixed today...Thanks
 

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Discussion Starter #16
There is a red number on each line. The top latch is 30 and 90. I traced them back to the manifold and took out the 30 and 90. The manifold has a small number etched in as well to correspond to each hose.

I am on my way to go pickup the new cylinder with lines. There is an almost impossible connecting point between the roof and trunk that has all the lines and wires running through...I cannot get to it, atleast not without manually opening the roof which it is still stuck. I am going to cut the lines in the headliner and cut the lines in the trunk and re route 2 new lines through an easier spot to the new cylinder...ideally missing the whole closing and opening roof system.

I am hoping that once I connect everything back together and get pressure back in the system I am hoping the roof and trunk and everything opens and closes on its own power. I am also hoping that just cycling the pump takes out all the air. I am still wondering where does all the air go? Any hydraulic system, not a mercedes roof though, I have ever done you need to bleed the air just like brakes but your saying because its an electric pump or this model pump is self priming and self bleeding? Hope that works. I should have the new part installed in about an hour. Let me know if you have any other tricks for getting the pump to work at full pressure or to fill or to bleed the lines out. There is a screw on the side of the white reservoir that is where I am filling the oil into. Once it starts coming out it is full at its at the halfway point...sound good? Thanks again!
 

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2006 SL600
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Yep halfway full of fluid (up to the screw hole) is full.

I’m not sure where the air goes, but it goes somewhere else and you don’t have to worry about it :)

I’m guessing once you have the new cylinder in and fluid runs through, the stuck roof will work again. Fingers crossed!
 

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Discussion Starter #18
Thank you very much for your support...ended up having the roof open and close as new by mid afternoon. I did need to keep filling the reservoir and everytime I opened it there was air pressure so I think it comes out once you put new fluid in possibly? Either way once you get the layout of everything its not that hard. Piping is numbered, manifold is numbered and the hardest part was finding the way to get the 2 pipes back to the trunk and under and around the carpet back to the manifold. They really jammed up the pipes between the cab and the trunk. Ended up having to cut both ends then pull it through from both sides. Then had to open the roof halfway to feed the pipes through and see what I was doing and zip tie everything so it did not get smashed upon opening and closing.

Glad that is done...cost me about $700 in the end and took 2 days...if I was to do it again I could do it in 2 hours...Thanks again for all your help. Signing out...
 
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