SL55/63/65/R230 AMG: SL55 slow folding hardtop
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Joined: Feb 2016
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2004 SL55 AMG
SL55 slow folding hardtop
Today (on a very hot day) my folding hardtop started to move exceedingly slow. The fluid is fresh (less than 4 months old) and halfway up the reservoir (2004 SL55 AMG). Any ideas on troubleshooting or what could be the issue?
Ps-It DOES work! Goes up/Goes down...it just has gotten slower???
Ps-It DOES work! Goes up/Goes down...it just has gotten slower???
Last edited by Tomcat SL; Jul 21, 2022 at 06:23 PM.
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Joined: Aug 2010
Posts: 359
Likes: 291
From: Rockport, TX
2007 S65 AMG-Sold, 2007 SL55 P030 - 2016 GL450 - - 2017 AMG GTS - Sold - 2015 AMG S65
Vario Roof
Slowing down almost always means you are developing a very small hydraulic cylinder leak (causing pressure drop} and it takes awhile before you'll see the level in the oil level in the reservoir drop.
I have done several repairs of individual cylinders at different locations on different cars but in the end always ended up doing complete sets of cylinder replacements in order to stop repeat repairs.
After many y/tears of experience I now only will replace full sets as ones you get in there you might as well do them all.
Best H
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Senior Member
Joined: Feb 2016
Posts: 328
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2004 SL55 AMG
To reach all the hinges you'll have to remove the top covers next to the rear windows, when I do any roof maintenance I'll spray/put a small amounts of clear silicone lubricant on all of them.
Slowing down almost always means you are developing a very small hydraulic cylinder leak (causing pressure drop} and it takes awhile before you'll see the level in the oil level in the reservoir drop.
I have done several repairs of individual cylinders at different locations on different cars but in the end always ended up doing complete sets of cylinder replacements in order to stop repeat repairs.
After many y/tears of experience I now only will replace full sets as ones you get in there you might as well do them all.
Best H
Slowing down almost always means you are developing a very small hydraulic cylinder leak (causing pressure drop} and it takes awhile before you'll see the level in the oil level in the reservoir drop.
I have done several repairs of individual cylinders at different locations on different cars but in the end always ended up doing complete sets of cylinder replacements in order to stop repeat repairs.
After many y/tears of experience I now only will replace full sets as ones you get in there you might as well do them all.
Best H
Have you ever tried a hydraulic "leak stop" additive?
Have you ever had the solution be to replaces the pump? (How do you test pump source pressure?)
Last edited by Tomcat SL; Jul 22, 2022 at 08:32 AM.
Senior Member
Joined: Aug 2010
Posts: 359
Likes: 291
From: Rockport, TX
2007 S65 AMG-Sold, 2007 SL55 P030 - 2016 GL450 - - 2017 AMG GTS - Sold - 2015 AMG S65
Additives > at best a temporary fix for me the are a waste of time and money
Pumps > I have not had any failures, perhaps those that run excessively due to the fact they were serving a leaking system for to long will fail eventually.
I also have remote operating (using the cars key fob) capability installed (https://www.mods4cars.com) on mine and for those that I take car off.
Best H
Thread Starter
Senior Member
Joined: Feb 2016
Posts: 328
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2004 SL55 AMG
Source > https://www.tophydraulics.com/
Additives > at best a temporary fix for me the are a waste of time and money
Pumps > I have not had any failures, perhaps those that run excessively due to the fact they were serving a leaking system for to long will fail eventually.
I also have remote operating (using the cars key fob) capability installed (https://www.mods4cars.com) on mine and for those that I take car off.
Best H
Additives > at best a temporary fix for me the are a waste of time and money
Pumps > I have not had any failures, perhaps those that run excessively due to the fact they were serving a leaking system for to long will fail eventually.
I also have remote operating (using the cars key fob) capability installed (https://www.mods4cars.com) on mine and for those that I take car off.
Best H
I am not seeing any obvious leaks/drops/moisture BUT I will keep looking.
Does the STAR system read hydraulic pressures/failures/leaks?
My top now takes 33-34 seconds from initial button depress to completely locked and dash saying top closed.
Senior Member
Joined: Aug 2010
Posts: 359
Likes: 291
From: Rockport, TX
2007 S65 AMG-Sold, 2007 SL55 P030 - 2016 GL450 - - 2017 AMG GTS - Sold - 2015 AMG S65
Search order for leaks
No STAR does not.
It may be a pin hole in any one of the cylinder seals with hardly any noticeable fluid loss in your reservoir but the pressure drop in the system is the reason it takes more time to open/close it and depending on how often you close and open the roof (& temperature) it will accelerate the point and time where it will fail.
A life cycle of 10-12 years is perhaps as much as can be expected for any one of these cylinder seals. I just completed the replacement of all cylinders on my 2007 and now have a 2009 in house that needs the same.
There really is no band-aid solution for these things ones it shows tell tale signs of failure your better of to plan for a full replacement if you like to have a convertible top that works every time you want to.
Best H
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