Hello, I am new to this forum. However, I have been on many times to check various topics related to r129 which I found very helpful.
The problem I have is related to roof top and the roll bar operation. I purchased the car last year with evident leaks from the front cylinders and the seller told me to replace them and everything will work fine. Well, I did that and leaks stopped (from operating the roll bar) but the top didn't go up. I changed the CU (serial ending 2426) with one ending with 0097. Now the top works fine but not the roll bar?
In addition to completing your profile, a meaningful thread title will get your question viewed by a lot more people that may be able to help you (and will make it easier for others to find answers to a similar question in the future). In this case "Roll Bar Not Working After Controller And Cylinder Replacement" would probably be a lot more effective than the generic "1994 r129 SL500".
tdoriot and SW23185, thank you for your useful remarks.
A concise title helps others in the future and makes this forum more useful (yet). Adding at least the location and model to the profile, makes it more pleasant for everyone following the thread, and it provides details that oftentimes make it easier to help. For example, a model year 94 in England has roll bar function and soft top function combined in the same controller (controller p/n 129820-2526), whereas a US model '94 does not (controller p/n 129820-0097 or 129820-2426).
Originally Posted by Mac1112
I purchased the car last year with evident leaks from the front cylinders and the seller told me to replace them and everything will work fine. Well, I did that and leaks stopped (from operating the roll bar) but the top didn't go up. I changed the CU (p/n ending 2426) with one ending with 0097. Now the top works fine but not the roll bar?
welcome to the forum!
It appears that the front lock cylinders where in very bad shape if you experienced hydraulic fluid leaks above the windshield just from operating the roll bar. I am glad that the top is now operational. Chances are, you will find the remaining ten cylinders in the rear leaking already, or starting to leak in short order.
A US model '94 (with controller p/n 1298202426 or p/n 1298200097) has a separate roll bar controller. The following is possible:
1) Soft top operation has not finished - the roll bar will not be operable if the top has not completely opened or completely closed and locked. Do you hear a warning chime when you start driving?
2) Communication between soft top controller and roll bar controller is impaired. Of course there could be a problem with the replacement controller -0097. Controllers 1298200097 and 1298202426 are interchangeable. (You can find controllers p/n 1298200097 in late model year '94 production.) However, I would check first whether there is a problem with the connectors or the wiring. Do you see any corrosion on the connector pins of the wire going to the roll bar controller or on the soft top controller? Did the same controller actually work on another car?
Hope this helps and looking forward to your response,
Sw23185, thanks for the tip, I will be more precise next time, it was a rookie mistake.
Also, thank you Klaus for your response. Ok, here is the full story:
After moving from Chicago to Dubai, the first thing I did was to enjoy the beautiful sunny days of Dubai, specially during the winter time. The Sl was my choice.
The car is a Japanese model and the previous owner had replaced all the top cylinders except the two front ones. Replacing them took care of all the leaks. However, the top didn't work, but the roll bar did. There were no lights or warning chime. A mechanic told me to replace the control unit located in the back seat, which I did with a used one, however, with a different p/n ..........0097 (the previous unit had a p/n ......2426).
Now the top fully operates without any warning lights and opens and closes normally, but not the roll bar! I reinstalled the old one just to make sure, again, the roll bar worked but not the top. I tried to reset the top by holding down the window buttons at no avail.
I reinstalled the newer one and held the roll bar button for 10 sec without any change. I don't have any warning lights or chimes. Everything looks normal. Also, I need to mention that I looked beneath the backseat for a roll bar control unit and I couldn't find one. I am beginning to think that the p/n......0097 is the wrong one for this model. Unfortunately, I haven't found another replacement here in Dubai since parts for this car are hard to find.
replacing front lock cylinder second time & controller compatibility
Originally Posted by Mac1112
The car is a Japanese model and the previous owner had replaced all the top cylinders except the two front ones. Replacing them took care of all the leaks.
Okay, that means the front lock cylinders have just been replaced for the second time. (There is no way the front lock cylinders have the original seals from 1994 if the rear cylinders have already been replaced.) For Mercedes convertible owners in Dubai (and many other hot places), we are already upgrading full sets of cylinders on cars that are only five years old. The heat accelerates the seal decay - it's a bunch of chemical reactions. This is not just a problem with R129s, but with all modern convertibles having automatic, hydraulic tops. Thus, please keep an eye on the rear cylinders if the previous owner did not use Top Hydraulics.
Originally Posted by Mac1112
I don't have any warning lights or chimes. Everything looks normal. Also, I need to mention that I looked beneath the backseat for a roll bar control unit and I couldn't find one. I am beginning to think that the p/n......0097 is the wrong one for this model.
Just to clarify again: if your car had a p/n 1298202426 soft top controller before, then it has a separate roll bar controller that communicates with the soft top controller. It appears that your roll bar controller is functional.
I have not heard of the 1298202426 and the 1298200097 not being compatible. Do you find any corrosion on the -0097's output pins, or does it look rough by any means?
Maybe i could take a look at it sometime and let you know what needs to be fixed (iv change my soft top 3 times!!) and you get to know the ins and outs of it pretty fast
As for replacing the seals, i wouldn't trust any shops in the UAE. A common thing they do here is to use bathroom sealant to prevent leaks. What i usually do is look for cars being parted out on ebay or craigslist, purchase the cylinders then forward them to Klaus and have them rebuilt and sent to my forwarding address or have a friend or family put the cylinders in their luggage when they head state side then forward them to Klaus.
Its the cost of living here, let me know if i can help you with anything else
"Understeer is when you hit the wall with the front of the car, Oversteer is when you hit the wall with the rear of the car, Horsepower is how fast you hit the wall, Torque is how far you take the wall with you."
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.