Greg Townsley

I have a 92 500sl that the hardtop switch will not work to remove the hardtop. It works to latch the top, but not unlatch...

Looking for info on the cause?

thanks!!

BJonesFL

Did you check the hydraulic fluid level at the pump in the trunk?

You can always use the tool that came in the MB toolkit (long handle allen wrench) to manually release the front latches.

kmitchell

What do you get when you try to unlatch it? Any sound or movement?

Bad Switch?

Bad Latch sensor?

Bad control module?

Does it latch and unlatch the soft top?

kmitchell

Hi Greg,

I got your PM and copied it below so others can follow this thread and also try to help.

===========
Thanks for your response to my question...

I haven't had an opportunity to check on the hydraulic fluuid level yet, but when i try to unlatch the hardtop it does nothing, nor do I hear anything when using the button. I can hear it engaging when attempting to latch, nothing when trying to unlatch.

Not sure what it does with the softtop because i haven't been able to remove the hardtop

Thanks again for your suggestions/help!!

Greg
==============

We need to start with the low hanging fruit.

1. Make sure you are following the exact sequence in the owners manual.

- Parking Brake Engaged
- Both Doors Open
- Rear Window Defroster unplugged
- Within 10 seconds of turning key in steering lock to position 2 (engine not running), slide soft top switch back and hold.

(I've been bit at least twice by trying to unlatch the HT with the engine running and it will not work.)

2. Check the fluid level and fill if necessary.

3. Manually unlatch and remove the hardtop so we can test the softtop operation.

Let us know how it goes and we'll continue from there.
Ken

jgines

Hi! Guys. I have 1991 with the same problem with you GREG. I just bought this car it was working by a week but when I put the hard top and leave it for 2 days. It wont work anymore,even the window does not go down automatic when you press down the switch.
any suggestion?where can I found to fill the hydraulic?

BJonesFL

The hydraulic pump for the top is in the trunk, under the spare tire.

Does the top up/down button flash when you try to use it?

Bob

BJonesFL

By the way, if anyone needs an owners manual and/or a radio operations manual for your model year 129, go to this site and download copies.

http://www.benzworld.org/forums/r129...ml#post2391320

Bob

jgines

only the top but not down.

BJonesFL

I don't understand what you're saying...would you try again?

Bob

jgines

You was asking me if Does the top up/down button flash when you try to use it? I tried but its not flashing at all.

BJonesFL

The top up/down button should flash once briefly when you first start the car.

When you operate the top to either put it up or down, the switch should light and stay lit until the cycle is complete. This button is not a '1-touch', you have to pull it toward you and hold it (for removal) as the top cycles.

Since yours isn't lighting at all, 1st, check all the fuses in the front and rear of the car using known good ones, test each fuse for the top system. The specific fuse slots for the top and windows should be printed under the cover of the fuse boxes.

If the fuses check out to be OK, then I'd move to the top controller located behind the passenger seat, under the parcel shelf and start pulling diagnostic codes from the maintenance port.

Last question, did you recently change your battery by any chance?

Bob

jgines

Bob, I got the hardtop off. thanks for your help, but now the hydrulic does not work. I bring the battery to auto zone and its good and fully charge. I check the fluid also and its more than half of the tank. What should be wrong now?

BJonesFL

What happens now when you pull the top up/down switch? Can you hear the pump running? Fluid level should be up to the 'full mark' on the side of the reservoir. Is the switch illuminated? (If it never lights up, this is an electrical problem. You can try re-synching the windows, sometimes this works to get things going.

o Close the doors

o Start the engine

o Whichever position the windows are in, you want to push and hold both window switches at the same time and move the windows in the opposite directon from where they are. When the movement is completed, continue to hold the switches in position for a count of 3

o Next, pushing both window switches simultaneously again, move the windows in the opposite direction. Again, when the windows are back to where you started this little test, continue to hold the buttons down for another count of 3...then release

o Turn off engine w/key all the way off.

o Wait about 10 sec. and re-start the car. Try the top up/down button again.

let me know what happens along with any noises, motors humming, movements, flashing lights, etc.

jgines

I tried what you told me. When I press the button up/down the light will on but not flashing on up position, but the light not on for down position, but the window will go up/down. There no noises or humming from the motors. What kind of Hydraulic fluid I need to get?

BJonesFL

The hydraulic fluid comes in 1 liter bottles and is available from Mercedes Dealer for around $20, or from any of the online MB parts sites along with Febi brand, the OEM of the MB stuff, p/n #02615, for about $13.

Bob

jgines

Thanks for info. Do you think the fluid was the problem? I will try to get from the dealer this weekend.

BJonesFL

Fluid the problem? It's possible. If the system is underfilled, the hydraulics don't create enough force to operate the top.

That said, let me add that if this were my car, I would find a trustworthy independent MB shop that has the Mercedes Star Diagnostic System, and can pull Diagnostic Trouble Codes(DTC's) from your top controller. I believe the core of your problem is either electrical in general, and/or the controller specifically.

One thing you can try is to cycle the top up/down manually (as described in the owners manual) with the 'special tool' in the toolkit. I've only read about, but never tried this procedure that some say serves to 'reset' the sytem. BUT, if you have DTC's stored in the controller, they need to be cleared/erased in order for the controller to even begin to operate, manual top reset or not.

So, I'm back to my earlier comment, it's time to see a trustworthy tech who knows these cars, has the STAR Dianonstic tool that can tell you exactly what's wrong.

If you want to read/learn more about the top system, the controller, diagnostics you can do, etc. check out this thread from another forum, it's quite good-

http://www.benzworld.org/forums/r129...ml#post2419223

Bob

CaptChris

One question, when you pull the button, are the windows going down?
That is the first step that should happen before the roof pops up.

Good luck.

Chris

esparza27

i was hoping you guys can help me with my problem..
on monday i manually removed the hardtop, easy... allen wrenches nd pliers for the rear latches(yes i know im suppose to use the tool) but i didnt apply much force for me to think i bent or broke something. when i put the hardtop back on the latches were in the up position, then i locked the front latches with the allen wrenches. my only concern is when i bring the rear latches down i am still able to lift the rear as if it wasnt locked...

Top Hydraulics

esparza27,

A few pointers:

1) Before locking the front, you want to be sure that the flexible prongs in the rear of the hard top were actually going into the rear locks/latches. If you were able to move the locks with your "tool", then the prongs were indeed in the locks.

2) Make sure the ignition is OFF. If the ignition is ON, then it will block the valves in the hydraulic system. Thus, with the ignition ON, you may just not be able to close the locks far enough. (Just in case, if the rear cylinders are leaking or if there is already a lot of air in the system, then that would explain why you might be able to move the locks at all with the ignition ON.)

Since you are opening and closing the top manually, there is obviously a problem with the hydraulic system. Please allow me to comment as follows:

Please be respectful of your automatic "RST" system - it is excellent when it works, it will most likely outlast the car if you have the cylinders upgraded, and it will raise the resale value of your car significantly. If you bought the car cheaply because the top didn't work, be glad you found this forum and please regard fixing the top as an opportunity to create equity!

I have to admit that I have used pliers before on junk car top locks, but I was extremely careful with them. It is very easy to break off the spot welded tabs on the rear locks.

Once again, manual locking and unlocking is an emergency operation. Manually locking the hard top is particularly rough on the rear locks. The system was not designed to be used this way frequently. In time, you are very likely to break or wear out locks, and you risk damaging the rear of the soft top when folding it into the storage compartment manually.

If your hydraulic system does not work any more for lack of fluid, then you will not be able to lower the roll bar after an emergency deployment.

Klaus

www.tophydraulicsinc.com

Watchcame430

Hi all, bought a SL yesterday and have the same issue as the OP.
Was interested in your point on the battery ... It had a new one fitted before I picked it up.
I know the previous owner had the soft top working a couple of weeks ago, so it's all a bit odd.
How would a battery change effect things?

Watchcame430

Please ignore question ... I tried again as per manual and she popped up!
I swear I had done that to start with ...

ou1954

I need to remove my 1998 SL500 hardtop WITHOUT running the pump. Too much leakage in those two top cylinders, which I want to repair or replace.


Any help would be appreciated