Hey everyone, I'm having this issue with my '98 Sl500. We just had the front and rear locking cylinders rebuilt, then re-installed them ourselves, but now when trying to put the top up, the rear latch is overshooting the oval hole to lock in place! We had to push back with some force to get it aligned, but it still wont fully close what's wrong? what do i do so it doesn't overshoot the hole to latch in? how do i get it to fully lock in? Thanks In Advance For Your Help, It's Very Much Appreciated!! I attached some pictures to show what's going on.

Thank You!

 

I'm hoping to keep this thread alive. It appears that with the '98 at least there are 2 positions for the rear bow: one for storage and one for deployment. After I opened the tonneau manually for cleaning, I discovered that the RST will not complete the opening cycle because the rear pins will not align with the rear latch openings by at least one inch. All other system behaviors are nominal. All known troubleshooting and reset procedures have been completed ad nauseum. I've found a few references on various forums to this issue but the threads just die.

 

It can be adjusted, you will need to adjust the lid latches, the 2 that goes in the holes. Allen wrench

 

Thanks Interior! I was trying to defer that adjustment until I know whether there are indeed two positions for the rear bow: one for storage and one for deployment. My assumption is that the rear bow is in the storage (down) position while it needs to be in deployed (up) position. I can't imagine the rear bow would get so far out of alignment with one manual lift of the tonneau.

 

Thanks for the suggestion, Interior, but it was even simpler than that. Although it is clearly described here in multiple threads, I still somehow misjudged the angle of the Locking Pins and they were indeed bent at their base. At least I can put to rest the notion that there are two positions for the rear bow. There is only one position for the 98 SL500.

 

Thanks for your replies everyone, i did the readjustment, but no luck. after a few tries, the driver side rear lock went in and locked like a charm, but no luck on the passenger side. I ended up readjusting the height of where the latch goes into, and now both sides wont lock in. The problem is that the rear locks are going down before the rear section of the soft top comes down to lock in. basically, it's out of synch. i ended up taking both of the cylinders out, opened them to their full extent, put them back in... and now, the windows quit working, the roll bar light came on, and a solid red light came on the soft top operation. it's all dead. Im going to try to keep working on it, hopefully i'll figure it out! any solutions with you guys?
Thanks!

 

I just need to know how to manually lock my hard top down on the back !!
I have tried the "tool" with NO luck, it seems the receiver is not in a pre- engage position. Is there something I'm not seeing to lock the rear down manually ????/ Help ...

 

Jemzal have you tried a full reset? You can start with a simple power refresh at the battery and go all the way to the fuses and solenoids.

http://www.benzworld.org/forums/r129...noperable.html

 

Hey JJ, did you do the visual inspection? In case you missed this:

https://mbworld.org/forums/sl-class-...down-back.html

 

Thx GUYS !! I just bought my SL ... It needs a lot of work .. But only has 23k miles. After reading your posts and links .. I have my top working ... At least 50% !! I disassembled my hydraulic pump and got it working , roll bar working , cover will lock and unlock ... Now here's where I'm at ....the cover will open top will raise up about 50 % ( top is about vertical ) then pump shuts off . I'm guessing there is a switch of some type to tell the pump to keep pumping depending on the tops postion. ??????? That's where I'm at...... All Help is TRUELY appreciated !!!

 

There have been a few issues brought up about the rear locks, plus the thread has been hijacked a bit with a question about top operation. I will cover the rear locks, and ask that JJ98SL create a new thread about the top lifting only half way. (JJ98SL, in your new thread, please make sure to describe in detail which parts of the system have been worked on. You may use the location diagram http://www.tophydraulicsinc.com/diag...129diagram.jpg as a reference.)

Three issues have been brought up about the rear locks:
1) The prongs at the rear of the soft top didn't go properly into the oval holes of the rear locks. The soft top actually has solid prongs in the rear, which are hard to bend. Their position can be adjusted (by loosening the star bolts that hold the prongs to the rear of the top), but that is hardly ever necessary. If the soft top prongs do not line up with the rear locks, then something might be out of whack on your frame (unlikely), the prongs have been moved (you would know about it), or the front of the top hasn't closed yet. Remember: the top always locks in the front first...
The hard top is another story. It has flexible prongs in the rear that bend easily. You might have to straighten those out. Also, it is usually the hard top removal that can accidentally make one or both of the rear locks close when they are not supposed to. More about that below.

2) The height of the rear locks was incorrect. This will normally only be the case if you have removed the rear locks before, or made some adjustment to the rear lock position, or freshly obtained a new (to you) hard top.
The rear locks are held in place by three 10-mm hex nuts. The locks are height adjustable when loosening the nuts. Sliding the locks up will make it easier to catch the rear of the top, and sliding them down will create a tighter seal in the rear. The hex nuts leave marks on the locks that show you where the locks were at initially - that's a good starting point.

3) One or both of the rear locks on model years '95-'02 are closed without the top being in it/them. It's a bit of a design flaws in model years '95 and younger, where one micro switch was omitted in the rear locks. The rear locks are designed such that they (normally) cannot be closed hydraulically without the rear prongs from the top pushing down into them. They can accidentally lock without the top in them (and freeze operation of the whole system), in the following cases:
A) The hard top was removed and the button was not pulled back long enough. This allowed the rear latches to open part way without activating the catch that prevents them from closing again without the top in them.
B) The rear locks were opened manually by pulling the release lever in the rear. If the locks do not get properly reset, then they WILL try to close as soon as you activate the top. That may result in the system freezing up.
C) The rear locks have been removed to replace hydraulic cylinders, and the locks have not been properly reset. Top Hydraulics always puts the reset instructions on the bags containing the rear locks or rear lock cylinders for model years '95 and younger, btw, plus we always ship the rear locks in reset position.

How can you tell if the rear locks are open or closed? Simple. Look down the oval hole of the rear lock, near the edge of the trunk. If you see a metal bar near the top (about 3/4" down the hole) that goes in the direction of front-to-rear of the car, then the lock is open. If the same bar (which is the receiving mechanism for the rear prong) is way down, then your lock is closed and MUST be properly reset.

I just thought of the probably easiest way to reset your rear locks on model years 1995 through 2002 (including model years 1994 in most countries outside of the US):

Step 1) Ignition off. Pull the release lever in the rear of the lock, pull up the locking mechanism (grab it with a hook or carefully push it up with a screwdriver while holding the release lever up). Make sure that both locks are open. That is not all - if you activate the top now, then the lock will close again right away and you're back to the beginning.

Step 2) Manually close the top, which includes locking the front first, and locking the tonneau cover, without locking the rear yet.

Step 3) Lock the rear of the top with the hydraulic pump, but make sure the rear of the top is pushing into both rear locks before you activate the system - you may want to have someone pushing down a little on both sides of the top's rear while you are pushing the red button forward.

If the above procedure doesn't work for you, then you need to take out the rear locks and reset them manually. To take out the lock, follow these instructions: http://www.tophydraulicsinc.com/R129...%20Removal.pdf The manual reset is a two-step process. First, pull the release lever in the rear and open the lock. Second, and very important, push the already open lock with your finger at the end of the chromed cylinder shaft as shown below, until you hear that second click:



Just for completeness, I am including the location diagram for all hydraulic cylinders below, and some instructions on how to access the release lever on model year '95-'02 rear locks.






Hope this helps,

Klaus

www.tophydraulicsinc.com

Applicable part numbers for R129 hydraulic cylinders:
1298001672 aka A 129 800 16 72, mounting in front latches p/n 1298000774 and 1298000874 1298000072 aka A 129 800 00 72, mounting in tonneau cover latches 1298000374, 1298000474, 1298001574, 1298001674
and rear locks 1298000574, 1298000674 1298002172 aka A 129 800 21 72, mounting in rear latches 1298001174, 1298001274, 1298001774 1298002072 aka A 129 800 20 72 1298000272 aka A 129 800 02 72 1298001772 aka A 129 800 17 72 1298001872 aka A 129 800 18 72 1248000272 aka A 129 800 02 72
1298000022 aka A 129 800 00 22

 

I am helping my friend with his 99 SL500 he first got the soft top in a bind on the way down and somehow managed to get it down the rest of the way then tried to put the hard top on but only got the front to lock and the back was sticking up and not locking.I was able to release the front locks with an allen and we got the hard top off. I think he tried too many times to release it as I read to many tries puts it in a safe mode where it wont work so we disconed the battery overnight and tried the next day but it really does not do much. The rb does not come up or down the windows do go up and down and was able to sync them. The right side cover latch is in the locked position and I cant get it to release. We can put the soft top up manually but no locking action and if its hydraulic shouldn't there be resistance cause it feels like the is no resistance from the cylinders when raising

 

krankenstien,

welcome to the forum! Where are you located?
It is admirable that you are trying to help your friend, and that you signed up to MBWorld in order to post your question. That's a lot of info in your post, and it appears that you guys tried a lot of ways to get the top working again. It would be awesome if you could put a little more effort into forming proper sentences and avoiding abbreviations, so that it will be easier to understand the description of the problem and the questions. That way, it is easier to help you, and future readers will benefit a lot more.

Here are a few questions that come to mind right away, and I would be great to get a response to all of them:

1) How did the soft top get into a bind on the way down in the first place? By chance, was the roll bar up, and your friend tried to move the top manually?
2) You say that you synchronized the windows. Just double checking: did they drop about 1/2 inch when opening the doors?
3) I am confused about the right side tonneau cover lock not releasing. Is it stuck locked without the cover in it? You should be able to unlock it with the soft top tool - make sure that the ignition is OFF.
4) Please double check that the front and rear locks are all fully open. Front locks cannot be turned with the Allen wrench when they are fully open. Rear locks can be inspected by looking down through the oval hole on top. If there is a metal bar going in front-rear direction about 3/4" from the top of the hole, then the locks are open. If one or both are closed, then please refer to my previous post in this thread dated 11-23-2013.

Klaus

www.tophydraulicsinc.com

 

Hi thanks for the reply Im located in Ocala Florida I found out that the problem started when he was putting the top up. It stopped halfway and would not go up or down from there so he put the soft top down by hand. He said the roll bar was up and it went down like it normally does. after that is when he put the hard top on and it would not lock down except on the front latches. When I said the windows were in sync they do go down when you open the door and go back up when you close it. I could not find a soft top tool and the guy who owns it doesnt know of one. I unlocked the right side tonneau cover latch and put it into the open position and made sure the rear ones were also open. Today we tried putting the soft top us as you described in the 11/23 post, the front latches locked when we pushed the top down. I had him turn the key on as described and tried to push down on the rear of the top onto the rear latches but felt no response. The pump only makes a slight noise when it is on but Im not sure how loud it should be as I have never heard it operate before this. I hope I have given you some good info but not too much

 

krankenstien,

thank you for the additional info. The easy way of solving this problem would be going to the dealer or an Indie with Star Diagnosis (SDS) who can read soft top controller codes, and having the codes printed out and erased. If you do, please let us know what you learned.

We may be able to solve this one still without Star Diagnosis, but with a few more clues. You seem to be pretty detail oriented, so I trust that the rear locks remained open when the hydraulic system got activated, before the rear of the top entered them. Let us know if they didn't.

Next question is, why did the top originally not finish its cycle - had any hydraulic cylinders been worked on, or had the battery been disconnected, or the car jump started?

Klaus

www.tophydraulicsinc.com

 

Hi Klaus and Happy New year Well the car has been in my garage for the past week and the other day I saw a small stain on the floor but when I looked in the trunk I really could not see much so when I got back on it today I had to remove his CD player out of the L/R wheel well to remove the carpet to get in there and found a nice pool of fluid down in there that had finally started to seep through the plug in the drain hole so I pulled the cover off the pump and the reservoir is empty. The switch for the L/R lock cylinder was off its mount and its wet. It has a hard line attached to a block with wires so I guess its some type of pressure switch. What kind of fluid do I need to fill the pump with and does it need to be bled so I can run it and see exactly whats leaking

 

Happy New Year to you, krankenstien, and all other readers!

I am assuming from your description that you noticed the connector for the wiring harness going to the left rear lock 1298001174 being off the square mounting bracket on the rear lock. That in itself is not bad. It might mean, though, that someone has tried to "fix" the hydraulic cylinder 1298002172 in the rear lock before and didn't succeed.

Having a massive hydraulic fluid leak normally means that the seals in the eleven hydraulic cylinders are pretty far gone. Keep in mind that the car is 15 years old. Model year '99 is currently pretty much at the peak of its hydraulic cylinder failure rate, if you average throughout the US. If you are seeing leaks in the rear, then this means in our experience that all cylinders with original seals need a rebuild. The good news is, it doesn't cost an arm and a leg if you can remove the cylinders yourself, plus Top Hydraulics' seals make the used cylinders better than brand new ones.

For hydraulic fluid, please stick with one of the following:
1) Mercedes fluid p/n 0009899103
2) FeBi 02615 (same as MB fluid, but without the dye)
3) Pentosin CHF-11S (available in some better part stores)

All fluids above can be mixed. There is no need to bleed the system. The air in the lines and cylinders will eventually be expelled into the reservoir.

Good luck, and please let us know what you find.

Klaus

www.tophydraulicsinc.com

 

Thank You I`ll get some fluid and see where that get us and whats leaking for certain. Im always relieved when I find a cause of the problem and if I don't know I`ll ask someone who does. Im like the fixit guy in my neighborhood and I get it all from horse trailers to head gaskets on an 86 Rolls Silver Spur. Whatever parts I need I`ll be certain to get them from you

 

OK I filled the pump and had mama hit the switch and the fluid is leaking from the left rear lock cylinder. I told my neighbor that I found the leak and what you had said about rebuilding all the cylinders but he says hes got his eye on a Hyundai equis....don't ask me why but hes got a plan to sell the 500 so he just wants to get the one cylinder done and let it fly. It looks like you pull the c clip off the pin and it comes out pretty is that true or is there something else I have to do

 

krankenstien,

here is a link to the removal instructions for the rear lock cylinder A 129 800 21 72: http://www.tophydraulicsinc.com/R129...%20Removal.pdf. All R129 cylinder removal instructions are located on our website's DIY section.

You are welcome to send the cylinder still mounted inside the lock - there is no surcharge on our end. You need to take the lock out of the car, anyway. If you want to remove the cylinder from the lock and send us only the cylinder itself, then you need a thin 7-mm wrench to unscrew the cylinder shaft from the lock (there is a 7-mm flat machined into the chromed cylinder shaft's end). Note that you should fully open the lock first (retracting the shaft), so that you don't hit the chromed shaft on a sharp edge of the lock upon removal of the cylinder from the lock.

Klaus

www.tophydraulicsinc.com
http://www.tophydraulicsinc.com/en/c...y-instructions

 

Hi,

I have same problem with my 1989 500SL. Rear locks don't work with hardtop. If I try lock ht-roof, rear locks usually don't lock.
If I try open ht-roof, lock's open but roof won't stay up position. It's rise but decent when I release switch. Front lock's working normally.
Soft-top work's fine, but same thing with rear lock's. I need try 2-4 times before locks open. Without that problem, soft-top work's fine.
Battery is new, hydraulic oil is full, cylinder's not leak. Any ideas what I should do? At local MB dealer not found any error codes.
Could that be RST-module?

Ville
FINLAND

 

See post #11, I was able to fix this issue on my car by resetting the rear locks. It's a bit tricky to get it right so read through it a couple of times and take your time.

 

Thank you for reply.
I read post #11, but it's about year's 1995-2002.
Is that same procedure that could be work earlier model's, my car is 1989 model?

 

Ville,

it is NOT the RST controller. You almost certainly have internal bypassing in the rear lock cylinders. The rear lock cylinders in your model year '89 are p/n 129 800 00 72, as opposed to p/n 129 800 21 72 in model years '92 and up. The piston seals are falling apart, and the hydraulic fluid can go directly from the pressure side to the return side without moving the piston much.

The same will happen to all the other locking cylinders in your top, as well: front lock cylinders 129 800 16 72, and tonneau cover locking cylinders 129 800 00 72.

To add insult to injury, Mercedes does not sell p/n 129 800 00 72 by itself, but only mounted in latches. Crazy, as there is no good reason for it. Mercedes will sell p/n 129 800 21 72 instead, and make you modify the locks to fit this bigger part. That modification includes New or properly rebuilt 1298000072s are in no way inferior to new 1298002172s, and cylinders rebuilt by Top Hydraulics are far superior to brand new cylinders from Mercedes.

You will not be able to find suitable piston seals for your cylinders.



Here is what we write on our website (please regard your European model year '89 as identical to a US model year '90):
"Model years 90-96 have twelve hydraulic cylinders that move and lock the roadster soft top. The original seals in the hydraulic cylinders, aka rams or actuators, will eventually fail in every R129, unless it gets wrecked prematurely, even if you never drive the car or have never used the top before.
Rebuilding these cylinders is NOT a matter of changing o-rings. Every R129 cylinder has one o-ring, and those rarely ever fail. What fails most frequently, are the other seals, which have special shapes for proper function. Top Hydraulics replaces and upgrades ALL seals in the cylinders with superior material:

1) Rod seals. They are cup-shaped and seal the piston rod from the rest of the cylinder. When they fail, you will see fluid coming out next to the chromed shaft (rod). These are usually the first seals to fail in the cylinders.
2) Piston seals. They seal the input and output sections from each other, as the piston slides through the cylinder. The piston seals have been made of different materials and sizes even in the same p/n cylinders throughout the years. Failing piston seals will cause internal leaks, which result in a pressure drop in your hydraulic system. Early model years have the added problem that the piston seals swell up and make it very hard to move the piston inside the cylinder. Crumbling piston seals can block valves or pinholes inside the hydraulic system, and it can be difficult to diagnose a piston seal failure without testing several cylinders once you find that your top is moving slowly or not at all.
3) Cap seals. These are just o-rings that seal the top cap of the cylinder from the housing. They are usually the last seals to fail, but these o-rings are penny items.
4) Port seals. They seal the hydraulic lines where they are pushed into the cylinders. Port seal failure is becoming more and more common as the R129s age. It also applies to the front distributor p/n 1298000022. Port seals have a special shape that makes them seal under pressure. O-rings wouldn't do the trick. They are secured by precisely machined brass rings (accuracy about 1/100 mm). DIY removal of the brass rings will almost certainly destroy the brass rings. Top Hydraulics installs port seals that are tighter than the originals, just in case the hydraulic line fittings have been scratched."


Klaus

www.tophydraulicsinc.com

 

Hi Klaus,

and thank you for help. Reason why I ask about RST-module, was that local MB dealer
guessing that could be reason why lock's won't work. We have so few SL's in Finland, it's really hard get help to problems at local dealers.
I also misslead because there is not any loss of hydraulic fluid.
It is also weird, that after 2-4 tries ht-roof rise and lock up, when I open it.
If there is bypass in rear locking cylinder's, could roof still work sometimes? After multiple tries?
What you think, should I change all locking cylinder's at same time or only the faulty ones?




Ville
FINLAND