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2003 SL500
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...There is a way to test these cylinders for internal leaks in the car, without the fancy Mercedes leak testing tool, but it is a better use of everyone's time to just have all three of the locking cylinders and the trunk lid frame cylinder rebuilt & upgraded at the same time...

Klaus
Klaus,

could you, please, describe how to test cylinders for leaks.

Thanks.
 

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03 SL Kleemann, 97 SL320, 95 E320 cab, Tesla X, Ferrari 360, etc
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Testing the vario roof locking cylinders for internal bypass

Klaus,

could you, please, describe how to test cylinders for leaks.

Thanks.
Okay, I will talk about internal bypasses on the vario roof lock cylinders below, as opposed to external leaks where you have fluid escaping the system.

As I mentioned before, four of the vario roof cylinders always get pressurized on one side when the top is moving. Those are the following:
Top lock cylinder A230 800 08 72, located in the top vario roof panel (hoses 30 and 90).
Left frame lock cylinder A230 800 09 72, located in the left forward corner of the trunk (hoses 33 and 93).
Right frame lock cylinder A230 800 10 72, located in the right forward corner of the trunk (hoses 34 and 94).
Trunk lid cylinder A230 800 13 72, located in the left rear corner of the trunk, behind the pump (hoses 32 and 92).

The top lock cylinder 230800872 and the two frame lock cylinders 230800972 & 2308001072 are notorious for piston seal failures, even fresh out of Mercedes' inventory. We are replacing them with a much more durable design and material, same as with the rod seals (the cup seals that the shaft slides through), and same as with the port seals (where the hoses go into the cylinders). If there is an internal bypass on the piston seals of one of these cylinders, then this will rob power from the pump every time the top gets activated.

Mercedes typically charges $650 to test cylinders for internal bypass. It is clearly cheaper to replace the candidates with rebuilt & upgraded ones shipped to you first from Top Hydraulics' inventory than to test old cylinders that will fail sooner than later, anyway.

Having said all of this, here is a fairly simple way to test for serious bypasses in your locking cylinders, with the top in closed position:
1) Unbolt the pump from the chassis, tip it over, and disconnect hoses 30, 31, 32, an 34.
2) Put the four disconnected hoses each into a ziplock bag or similar, re-secure the other hoses on the pump, and put the pump back into its original position. No need to bolt down the pump right now.
3) Close the trunk, get into the driver seat, ignition on (engine on or not), push the vario roof button forward/down as if to close the top further. The "convenience locking" feature will operate the pump for a couple of seconds and open the valves that divert fluid into lines 90, 91, 93, and 94. There will be a tiny bit of movement in the locking cylinders, just from compressing the weasther seals. This may cause a few drops to come out of hoses 30, 31, 33, and 34.
4) Repeat step 3) several times, because the pump runs only for a short time. If there is more than a few drops coming out of one of the hoses, then you positively have an internal bypass in the corresponding cylinder. Sometimes, bypasses become obvious only when the hydraulic fluid is hot, and the bypasses could also happen only when the locks are open.

alk247, I hope this answers your questions. What is going on with your top?

Klaus

tophydraulics.com

 

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2003 SL500
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alk247, I hope this answers your questions. What is going on with your top?

Klaus

tophydraulics.com
Klauss,

thanks a lot, it definitely answers my question with regards to the testing approach. As for my roof - I guess it is just a typical R230 roof aging problem. I know that prior owner had replaced the top locking cylinder. Roof worked fine, but around 4th of July on the day we we planning to leave for a long weekend (not in SL) I opened the roof on my drive from work home. I thought that roof was sort of jerking on the way up, but did not pay much attention to it, since I wasn't sure if it was any different from usual. When I got home and tried to close the roof, it only went up about a third of the way and stopped. I tried to move it back and force, and each time it wold move less and less. Eventually, though, it did go back into the trunk all the way. I had to clear space in my garage for the SL (Idea of leaving it in the driveway with top down did not appeal to me for some reason). After I came back after long weekend, I was able to manually close the roof. I found no fluid leaks anywhere in the car. Initially I thought the pump gave up, but when I was closing the roof manually, there was clearly pressure in the system, which most like would not have happened with failed pump (mechanical portion). The motor is running, so fuse is not blown. Then I read you post and realized that some of the cylinders are pressurized on both sides it became clear, that system may have some pressure, no leaks and working pump and still not operating the roof, but just pushing fluid around through leaking cylinder(s). So far it is just a guess, since I didn't even check the fluid level in the tank since July. Was busy with other things, so SL was just transformed into coupe for now. With winter approaching I hope to get to work on SL (this is by far not the only problem, but none makes it undrivable) and figure out what's wrong. And when I do, it will be your turn to fix the broken part(s):devil. Again, thanks a lot.
 

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1998 SLK 230
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Ok, guys
My 98 SLK 230 has a habit of not raising the roof after driving with it down for a while.
Here is what happens:
Pushing the button forward, the trunk lid raises then no other movement.
The pump is still working.
The hat shelf does not raise, which is the next step in the process.
Here is the thing I find puzzling:
After letting the car sit for 10 minutes, everything works fine.
How does this sitting period allow the system to correct the failure??
Surely it is not a switching or electrical problem.
Would it be computer related, or hydraulic?
 

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CURRENT: 2011 SL550, 2011 C300 FORMER: ML350, CLK550 Cabriolet, C240, ML320, 300TD
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Ok, guys
My 98 SLK 230 has a habit of not raising the roof after driving with it down for a while.
Here is what happens:
Pushing the button forward, the trunk lid raises then no other movement.
The pump is still working.
The hat shelf does not raise, which is the next step in the process.
Here is the thing I find puzzling:
After letting the car sit for 10 minutes, everything works fine.
How does this sitting period allow the system to correct the failure??
Surely it is not a switching or electrical problem.
Would it be computer related, or hydraulic?
You have an R170 SLK - you should post in that forum for the best answers.
 

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1992 500SEL, 2003 SL500
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Discussion Starter #26
My quest for the Holy Grail started years ago and hopefully has reached a successful conclusion. What is my quest you say? I want a vario roof that goes up and down when I press the buttons. I should soon have that, but this is a cautionary tale. It all started a couple years back when I lost the roof latch on my 2003 R230. Thanks to this forum and the internet I soon learned the failure of this ram would in turn lead to the failure of many. This sage wisdom came in no small part from Top Hydraulics in OR. Klaus has always and continues to provide us DIYers with the help needed to keep these systems functioning by upgrading the OEM seals that last about ten years under the best conditions. FL heat is not the best condition. Enough of that, the point of all this is for me to provide to you a very valuable lesson learned. For you see we are now going into my car to the third time to replace rams that I was sure would be OK. I did onesy twosy replacements on my rams and the cost and time lost would have more paid for the 'all or nothing' approach that TH suggests on their website. I thought I could get by with one but it turned out just as predicted they failed in domino fashion leaving me and my mechanic to go in over and over again until now until all rams got the upgrade. The last to fail was the roll bar pawl which was spraying HD fluid with wild abandon in the rear footwell of my beloved SL. So take it from me, and from Klaus, when one goes get the kit and go in just once. In my case it was pennywise and pound foolish. Regardless of your make and model Jags, Vets, Lambos, etc. TH has Youtubes for them all. Klaus tells me the R230 vid is in the works but hopefully I'll never need it again.
 

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Hi Klaus and Forum Team, just got all 11 cylinders overhauled by Tophydraulics, living in Dubai running a SL600 V12 first roof top lock cylinder and trunk started leaking - as always this is an indication of more to come. So decided to do a round robin taking all 11 out sending them to the US and amazingly less than 72 hours after arriving in their factory I received all items repaired back in Dubai - how was this even possible? Unreal service, faster than getting new parts shipped from Europe and certainly much less costly at about 300-400USD per cylinder. One area of further enhancement, as they seem to have amazing shipping support, would be interesting to tap into this by using their shipping logistics bringing goods in. Local shipment cost for 4kg from Dubai to the US was supposed to be 450 USD one way. Keep up the great work and look into more overhaul services like the ABS systems which always fails....talk soon.
 

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I hope this is the right forum …….I have a 2005 SL500......left side flap was drooping so I replaced the flat gear bracket......everything was great. I ran the top up and down 3-4-5 times...adjusted the flap. Ran it up and down 3 more times and everything worked great. Went inside to clean up...came back out and cranked the car....hit the button to lower the roof....nothing. Absolutely nothing. Message says "Visit Workshop". There is no hum.....no pump kicking in....no switches working....Nothing. Ive checked every fuse I know.....the rear battey is at 12.7 volts......ive checked for corrosion on the connectors at the PSE.....im at a loss. Any suggestions?
 

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Since you were working with the flaps, I'd guess one of the associated switches is signaling correctly. If you have a multimeter to measure resistance, reply back, and I'll suggest a test.
 

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'03 SL500, '03 SL55, '97 SL320, (2) '91 300SL, (2) '91 500SL, '00 S500 -- all for sale
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I've attached a schematic which depicts the flap switches in their state when the roof is closed. If you separate the electrical connectors I think you can see what continuity checks to make. S126/1 is the left-side switch, and S127/1 is the right.
Flap Switches.JPG
 

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Open the trunk and verify the flaps are up tightly to the underside of the trunk lid. Also make sure the retractable cover over the open trunk space is closed and engaged in the pockets at both sides.
 
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