cgstiefvater

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.

sushipaste

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.

cgstiefvater

Will do. Of course, if there is less than max fluid in the reservoir that would be indicative of a leak. If there are no signs of a leak, what might a logical next step be?

Thanks a lot.

sushipaste

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.

cgstiefvater

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.

sushipaste

you always go the top hydraulics rebuild route. New parts from Mercedes will total like $3k and the seals will fail soon anyways.

top hydraulics has prices on their site my mechanic charged me $900 labor to replace all cylinders

bttucker

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 :-)

Dubswayne

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

Ahmed

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.