Advice Buying 1999 500SL - soft top problem - PeachParts Mercedes-Benz Forum

skybound · #1 11-27-2006, 02:48 AM

Just tonight I went and test drive an absolutely immaculate 1999 SL500 with 78K miles. I have looked at quite a few SL500's over the last few months and I have read a lot here in the posts on what to look for. I tried everthing in the car (including the air conditioning) and then took it for a test drive. When the test drive was over I had the salesman help me take the hard top off and then tried to raise and lock the soft top. Everything seemed to work fine until the rear of the soft top was about 4 inches from the rear locks and it seemed to stop completely, there was a humming as if it was trying to lower itself into the rear locks but after several failed attempts to lower and then raise and lock the soft top the results were the same, just a humming when the rear of the top was about to lower completely into the rear locks. I even had the salesman try to assist the rear of the top down into the locks but it did not move more than a half inch or so. As far as I can tell it seems that maybe the haydraulic fluid may be low (not sure but I believe the mechanism that actually moves the top is hydraulic, but I could be wrong), that brings me to my next question. If the hydraulic system is what moves the top and the the system fluid is low that indicates a leak somewhere. The salesman told me he would have it looked at and give me a call. Any advice on what to look out for when I return to look at this beauty of a machine? I ran a carfax on this car and it has only had one owner and even though I did not look at the records myself the sales manager told me that the car did come with complete service records from the previous owner. I guess the most important thing here is any advice as to why the problem with the soft top occured and if anyone here knows what I should look for when I go to look at the car again. I don't want some mechanic pulling a fast one by filling the hydraulic reservoir when there is a leak; if indeed this is the cause of the problem. Any advice here is appreciated.

snowbilt · #2 11-27-2006, 10:37 PM

If I were you I would have them take it to a dealership and have it fixed, if it isn't at a benz dealership already. If they say it is fixed I would put the top up and down 20 times and/or make them give you a month grace on the top fix in writing. My question is if it is low on fluid how did it get low....LEAK!!!

skybound · #3 11-27-2006, 10:52 PM

Thanks for the reply, I talked to the dealer that is selling the car today (not a MB dealer) and he told me the car was taken to the local MB dealer to have the top repaired. Not a bad idea to get at least some kind of warranty in writing for the top even if for a limited time period. I am not sure that 20 cycles of the top at once is a good idea though, I have read in some other posts here that the pump can overheat if it is used excessively without time for it to cool down. The possibility of a leak still does concern me though, maybe I should ask to see the invoice for repair and what was actually done.

Gilly · #4 11-27-2006, 10:59 PM

If the top was down for an extended time, with the hard top on, the system can get air in it. Best course of action is to let it sit in the failed mode (inside) overnight, it will purge itself of air, should work next morning.
Gilly

stats007 · #5 11-28-2006, 10:21 AM

What can get air in it? The hydraulic system?

The system has in built protection and will shut down if the voltage is too low or it it overheats slightly - so don't worry about that.

DanielG · #6 11-28-2006, 11:50 AM

Ask your dealer which MB dealership they sent it to and then call them to ask about the top, what was wrong, what they were authorized to do and the prognosis for its continued functionality. If the car is still there you might ask them to do a complete check of the car (at your expense) -- to find out all you can about its condition.

Gilly · #7 11-28-2006, 04:06 PM

Yes, air gets in the hydraulic system, not sure how it gets in, I'd assume gets past the seals somewhere. Air can get in, fluid can't get past the seals though (to leak out).
Gilly

Larry Z · #8 11-28-2006, 09:44 PM

Had the same issue you are seeing on my 99sl this past spring. A new battery was needed. Problem solved

skybound · #9 11-29-2006, 12:17 AM

Just wanted to say thanks to everyone for all the input here, nice to have so much knowledge of this board. I know I have saved myself a lot of headaches and time in maintaining my 94 E320 with tips I have gotten here. I will post a reply when I find out what the cause was when find out more.

stats007 · #10 11-29-2006, 09:36 AM

Quote:

Originally Posted by Gilly

Yes, air gets in the hydraulic system, not sure how it gets in, I'd assume gets past the seals somewhere. Air can get in, fluid can't get past the seals though (to leak out).
Gilly

I've never heard of that being a reason for the soft top bow not locking. Air in hydraulic fluid will cause the system to be noisier and slower but not stop altogether - fluid is harder to compress than the air for a start.

Carlos Serrano · #11 11-29-2006, 02:02 PM

My 199 SL 500 soft top acts up after is been in the storage compartment for extended periods of time, hurricane season, winter etc. and it usually takes quite a few tries before it gets back to normal, last year the clamshell cover lock woudn't release, I use the top tool from the tool kit and manually unlocked it lubricated the moving parts and from then on no problems, the previous year the same problem you have , I kept going thru the cycles till it finnaly started to work on its own as far as I can tell the soft top mechanism just get stiff after extended stay inside the compartment and maybe that its all wrong with it, hopefully.

Gilly · #12 11-29-2006, 06:40 PM

That happens here up north alot, where people will put the hardtop on in the winter, possibly driving the car if it's not too snowy, then taking off the hard top in the spring. MB said in situations like that you can get air in the system. The best course is to force the locks to lock (with the tool) and let it sit overnight with the locks locked. Works like a charm.
Gilly

page62 · #13 11-29-2006, 07:05 PM

From the sounds of it, this is likely a minor issue. So many R129's (and R107's for that matter) never have their hardtop removed. And this leads to all sorts of soft top maladies.

If this car is a beauty...and the price is right...beat that dealer down to a good deal. Then buy it! It's December, and the convertible market is a wee bit slow...

snowbilt · #14 11-30-2006, 07:23 PM

I am waiting to hear the outcome of your problem. When I said try it 20 times I meant within a reasonable time frame. Also, I have never heard of air getting in the hydraulic system. I am not saying it can't happen but I have been a member of "the other" board for a while and haven't seen this mentioned there either. I agree on the fact that I would find out what dealership worked on it and call them and ask for a copy of the invoice.

Gilly · #15 11-30-2006, 08:40 PM

We had this happen on new ones that sat on the lot without being sold, all winter. Salesmen had demonstrated the top to the new owners in the spring, with results like this. MB tech hotline said that this is what was happening. We did what they said and top worked fine the next day. Not really impressive to the new owners. Happened a few times. After that first one, we had a few owners of older 129s who were also reporting non-operation after taking off the hardtop after a winter of the softtop in the storage boot, we fixed them the same way, often after needing to disconnect and reconnect the control module, also per the MB hotline.
Gilly