SL/R129: 1999 SL500 Hardtop Will Not Come Off, Roll Bar Stuck
Thread Starter
Newbie
Joined: Jul 2021
Posts: 3
Likes: 0
1999 SL500
1999 SL500 Hardtop Will Not Come Off, Roll Bar Stuck
Hello all,
I recently purchased a 1999 SL500 with ~130k miles. I have very little knowledge of its history or any previous issues, though it seems to have been taken care of, at least from a cosmetic standpoint. I have reason to believe that the battery was dead/low for a period of time, and I am aware that can cause some issues with the top operation
My hardtop currently does not open, and my roll bar is stuck up. I have re-synced the windows, and tried to reset the roll bar by pushing the button for however many seconds, both to no avail. Upon pressing the roll bar switch, I hear a slight click along with a low pitched hum, however the bar does not move in either direction. Upon pressing the top operation switch, the car makes the same noise, windows come down but nothing else. Also, upon starting and driving the car a short distance, I get a 'seatbelt' beep, despite my belts being fastened. This may be due to a bad belt pretensioner that may be the cause of an SRS light I have on the dash, but figured I would include it. I have not been able to connect the car to STAR unit as of yet.
I have not tried disconnecting and reconnecting the battery just yet, and have not had a chance to replace the trunk fuses. I will update this thread as I troubleshoot. All that said, does anyone have any idea as to what the problem may be/have any insight that may point me in the right direction? I would rather not take this car to a Benz mechanic who will likely charge me $500 just to tell me I need >$1000 in repairs.
Thanks a lot.
I recently purchased a 1999 SL500 with ~130k miles. I have very little knowledge of its history or any previous issues, though it seems to have been taken care of, at least from a cosmetic standpoint. I have reason to believe that the battery was dead/low for a period of time, and I am aware that can cause some issues with the top operation
My hardtop currently does not open, and my roll bar is stuck up. I have re-synced the windows, and tried to reset the roll bar by pushing the button for however many seconds, both to no avail. Upon pressing the roll bar switch, I hear a slight click along with a low pitched hum, however the bar does not move in either direction. Upon pressing the top operation switch, the car makes the same noise, windows come down but nothing else. Also, upon starting and driving the car a short distance, I get a 'seatbelt' beep, despite my belts being fastened. This may be due to a bad belt pretensioner that may be the cause of an SRS light I have on the dash, but figured I would include it. I have not been able to connect the car to STAR unit as of yet.
I have not tried disconnecting and reconnecting the battery just yet, and have not had a chance to replace the trunk fuses. I will update this thread as I troubleshoot. All that said, does anyone have any idea as to what the problem may be/have any insight that may point me in the right direction? I would rather not take this car to a Benz mechanic who will likely charge me $500 just to tell me I need >$1000 in repairs.
Thanks a lot.
Last edited by cgstiefvater; Jul 6, 2021 at 06:02 PM.
Senior Member
Joined: Mar 2020
Posts: 253
Likes: 46
From: Riverside, CA
1999 SL600
Go into the trunk. Remove the carpeting and then the spare tire. Underneath is a plastic cover for the hydraulic fluid reservoir for the roof system. Check the fluid level and stop using the roll bar or top buttons until you verify that there is hydraulic fluid at the max level in the reservoir.
Thread Starter
Newbie
Joined: Jul 2021
Posts: 3
Likes: 0
1999 SL500
Go into the trunk. Remove the carpeting and then the spare tire. Underneath is a plastic cover for the hydraulic fluid reservoir for the roof system. Check the fluid level and stop using the roll bar or top buttons until you verify that there is hydraulic fluid at the max level in the reservoir.
Thanks a lot.
Senior Member
Joined: Mar 2020
Posts: 253
Likes: 46
From: Riverside, CA
1999 SL600
because it sounds like your pump runs yet nothing moves I’m guessing you have bad top cylinders that leaked all the fluid and your reservoir is dry (fluid can leak from the sunvisor area or by the rear wheels). If it’s dry refill with mb or febi 343 hydraulic fluid, if fluid leaks out and top still doesn’t work, your fix is replacement of all 11 top cylinders.
I had the same exact problems as you with my 99 600. All 11 top cylinders had to be replaced last week.
Thread Starter
Newbie
Joined: Jul 2021
Posts: 3
Likes: 0
1999 SL500
you only have a leak if the fluid is below min level. If the fluid is in range you’re ok and that means a potential fault code or electrical issue that needs investigation
because it sounds like your pump runs yet nothing moves I’m guessing you have bad top cylinders that leaked all the fluid and your reservoir is dry (fluid can leak from the sunvisor area or by the rear wheels). If it’s dry refill with mb or febi 343 hydraulic fluid, if fluid leaks out and top still doesn’t work, your fix is replacement of all 11 top cylinders.
I had the same exact problems as you with my 99 600. All 11 top cylinders had to be replaced last week.
because it sounds like your pump runs yet nothing moves I’m guessing you have bad top cylinders that leaked all the fluid and your reservoir is dry (fluid can leak from the sunvisor area or by the rear wheels). If it’s dry refill with mb or febi 343 hydraulic fluid, if fluid leaks out and top still doesn’t work, your fix is replacement of all 11 top cylinders.
I had the same exact problems as you with my 99 600. All 11 top cylinders had to be replaced last week.
Thanks for your help.
Senior Member
Joined: Mar 2020
Posts: 253
Likes: 46
From: Riverside, CA
1999 SL600
Will have a chance to go all through the car tomorrow. Hopefully I will not have to get the same repair, but it seems like I will have to. Out of curiosity, did you replace the cylinders with new parts, or did you go the rebuild route? Either way, what did this repair cost you?
Thanks for your help.
Thanks for your help.
top hydraulics has prices on their site my mechanic charged me $900 labor to replace all cylinders
Junior Member
Joined: Jun 2021
Posts: 53
Likes: 10
From: Columbia, MO
2001 SL500, 2017 GLE350
My cylinder replace labor charge was 13 hours at $75 each... so $975. Lots of trim to be removed/installed, installing the cylinders is not trivial, then checking/fixing so everything works right....I think it took more than 13 hours :-)
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Newbie
Joined: Nov 2021
Posts: 5
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R129
Always top hydraulics. and always just do all 11 or 12 cylinders.
May be your top control module. I replaced my module and roll bar was functional but still shows fault lamp
May be your top control module. I replaced my module and roll bar was functional but still shows fault lamp
Last edited by Dubswayne; Dec 28, 2021 at 06:52 PM.
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MBWorld Fanatic!
Joined: Apr 2002
Posts: 2,668
Likes: 211
From: Bahrain
R129 SL55 AMG & W208 CLK55 AMG
This is very common on 129's when either battery is weak or has been disconnected.
You have 2 options:
1. Use Star Diagnostic to reset the system.
2a. If soft is tucked inside, push on the compartment flap to make sure the pins are locked int otherwise the system will not operate.
2b. If the soft top is closed/hardtop fixed, push on the rear where the pins lock into the latches. (If this doesn't work, you may need to use the tool to remove hardtop/tuck soft top in and try 2a)
Then try again.
You have 2 options:
1. Use Star Diagnostic to reset the system.
2a. If soft is tucked inside, push on the compartment flap to make sure the pins are locked int otherwise the system will not operate.
2b. If the soft top is closed/hardtop fixed, push on the rear where the pins lock into the latches. (If this doesn't work, you may need to use the tool to remove hardtop/tuck soft top in and try 2a)
Then try again.
Last edited by Ahmed; Dec 29, 2021 at 02:20 AM.
