MrBlackCLK55

Hello World of W209 CLK Owners -

I purchased a CLK55 with a non-functioning top and no clue what has or has not been done by the PO. It has been a long winter of wrenching. So far...stripped the interior. Removed all the lift cylinders and sent to Klaus at Top Hydraulic (AWESOME CUSTOMER SERVICE / FAST TURN AROUND). Replaced micro switch attached to lift cylinder driver side rear and replaced micro switch near A-Pillar passenger side (ran codes when purchased, but in hindsight the old parts bench tested fine). Tested with a buddy for continuity from all micro-switches (except the ones near the A-pillars) to the N52 Module - all operated when manually manipulated. Tested for line continuity from N52 to the pump pins - all good. Purchased iCarsoft MB scanner V2.0 to read/clear codes - done.

Started car to operate top and same results. 1) the windows are already down. 2) the pump clearly runs but nothing happens. After a few seconds of running the pump turns off. Not a single cylinder energizes or moves. Its as if no fluid is going to the cylinders anywhere. That said, when I reinstalled cylinders I managed to pinch an O-ring passenger side for the cylinder that lifts the rear window and fluid was weeping which indicates fluid is being pushed. 3) trying the opposite direction on the switch the pump runs for a brief second but realizes everything is "closed" (top up protecting from rain) and turns off.

Has anyone had a similar experience? Bad N52? Bad solenoids in the pump? Bad....elsewhere? Since clearing the codes they have not come back.

Here are the initial codes that I think are related to the Top. I ran the first scan with the N52 disconnected intentionally trying to get a base line of fault. Since clearing the codes, none of the following have returned:
1) Code 9007, Historic, Switch N72s29(Power soft top switch) is defective or has been operated for longer than 25 seconds
2) Code B1926, Historic, Limit Switch "INTERLOCKED' of soft top compartment fails to switch
3) Code B1928, Historic, Limit switch 'INTERLOCKED' of soft top compartment cover remains in the switched condition
4) Code B1953, Historic, Limit switch 'Interlocked' of soft top fails to switch
5) Code B1950, Historic, Limit switch 'Catch position' of soft top lock fails to switch
6) Code B1951, Historic, The state of limit switch 'Catch Position' for the soft top is unreasonable
7) Code B1934, Historic, The state of limit switch 'Catch Position' for the soft top bow is unreasonable of the state of the limit switch for the soft top bow is unreasonable.
8) Code B1504, Historic, the current recognition of the right seat belt extender is faulty

Thanks for the help. I am sure this has happened to someone else out there. I'm not afraid to spend $ to get this going, I just don't want to start throwing parts at it in hopes the next part fixes the problem. Would rather buy the right part once or perhaps find the electrical gremlin that keeps evading me.

Here are my other testing notes and a video link below if it will upload so you can hear the pump operate. I also pulled the pump to confirm the O-rings on the base of the pump were not leaking. All was ok.

1. I did have an O-ring leak upon reassembly at the window lift cylinder. I cleaned up the mess and installed a spare.
   1. Good news: this means the pump is pushing fluid
   2. Bad news: the top still will not function after replacing the O-Ring
2. Pulled out the multimeter and worked my way to the N52 module
   1. First tested for continuity from the N52 to the pump -All wires had continuity
   2. Second tested micro-switches: For me, top CLOSED means the top is up and protecting the interior from rain and weather. All test performed with top CLOSED.

i. S84/3: pin 41 (grey/black) should be: s/c when top up (confused what they mean by “up”) - tested O/C Has continuity when manually operating micro switch – are these pins reversed?
ii. S84/13: Pin 44 (grey/green) should be: s/c when top up - tested S/C has continuity

iii. S84/23: Pin 44 (Grey/Green) should be: s/c when top up in series with S84/13 Microswitch - tested S/C has continuity

iv. S84/13s2: Pin 43 (grey/orange) should be: o/c when compartment closed - tested O/C

v. S84/22: Pin 30 (Grey/Pink) should be: s/c when catch - tested O/C has continuity when manually operating microswitch

vi. S84/15: Pin 36 (Red/Brown) should be: o/c when closed - tested O/C

vii. S84/15s2: Pin 49 (Red/Yellow) should be: s/c when bow down -tested S/C has continuity

viii. S84/19: Pin 35 (Grey/Violet) should be: s/c when bow locked (NOTE: PIN 45 is original call out. My Pin 45 is White/Black and is O/C when top CLOSED) - tested S/C has continuity
ix. S84/9: Pin 47 (Red/Grey) should be: S/C when luggage roll cover closed -tested S/C has continuity

Here is a video of the pump in operation: https://photos.app.*******/s4zRZN32mE9TnKY17

As you can hear, the pump runs, but nothing happens. Bonkers!

C280 Sport

Jesus that is awful. When I purchased my 2004 I was in the same boat. The previous owner was a real cobb jobber and messed EVERYTHING in the car up. I ended up replacing the entire top and all of its components including the canvas as well. It was like brand new ever since. Every link, ever moving part, hose and fluid as well. All the solenoids and the pump and even the gaskets around the window. Cost me a fortune but its not perfect.

Rudeney

I would try opened and closing to top manually a few times just to make sure everything works and the switches all get synchronized. Also, having all cylinders replaced, there's a lot of air in the system. It's self-bleeding, but it can take a while for it to works it out.

MrBlackCLK55

Thanks C280 & Rudeney. I manually operated the top several cycles last night moving each cylinder set several times. I was only able to get a helper to do the main top but a few times. The results...

1) When putting everything back to a "Closed" position (top up protecting interior from rain) the rear cover (the panel the rear glass window engages with) fought me going back down due to excessive hydraulic pressure. I had to remove one of the cylinder pins (passenger side) and manually push the cylinder in to free it up. I reconnected the pin and with the reduction in pressure on one of the cylinders the lid lowered.

2) Put all components back into operating mode, crossed fingers and tried pump. For the first time - ever - the whole top seemed to activate. Nothing happened but I could tell the cylinders were getting pressure. I call that progress!

Though the pump is self bleeding, does it do me any good to manually cycle the pump with the brass fill fitting removed catching any fluid that is expelled with a paper towel? I am now wondering if the pump itself has lost its prime due to the air in the system. The fluid seems opaque in the reservoir after operating - as if spinning bubbles. These settle out after some time. I am wondering if I have been pushing air in my lines all this time. Thoughts?

For now, manually cycling has gotten me farther than anything else. I am intending to continue tonight but would appreciate knowledge if I should do this with the brass plug removed ensuring I am not pressurizing the system with any air that is not expelled via the auto bleed system. Good news is I have become an expert in manually closing/opening my top this winter.

I've got to be close. Today is the warmest it has been since early October!

Rudeney

Yes, those cylinders for the lid can be very tough to manually operate. They revised them at some point (2006?) and they became a bit easier, but still very stiff, plus the angle of the lid pushing and puling on them is not goo, either. Detaching them from the lid is a good way to overcome this problem.

As for operating the pump with the plugged remove, that won't help. One thing to consider - make sure you have the lines connected correctly. It almost sounds like something is backward. Another thing to try - manually open the top, then try closing with the pump. Or even manually partially open or close it and then try operating it with the pump.

You may have this already, and it may not help here except for the sequence of things, but I'll link it anyhow:

http://benzbits.com/w209/soft_top/W2...gnosticAid.pdf

MrBlackCLK55

Thanks for the link! Yes, I've been using this and the other post's info on the forum a ton.

Is there a schematic showing which hydraulic line goes to which cylinder and which end of the cylinder at that? How about at the meter/manifold block on the pump? I had the same thought about having the lines crossed at the cylinder(s). I put everything back the way I removed them, but then again I do not know what the PO did or did not do in removing lines and possibly reinstalling backwards.

Rudeney

I have never seen a schematic for the lines, and I've check SDS and find nothing. Maybe Klaus has some docs?

rustybear3

Lesson learned: Before buying any used convertible, make sure the top is in good working order. The grief and expense in fixing them if non working is not worth it IMO.

nkx1

Or just buy a coupe lol. Especially the CLK, since it's pretty open with all windows down and the sunroof open.

MrBlackCLK55

Getting close Rudeney. Put top in Open position "interior exposed to elements" and went to close the top (good suggestion). It started to pull the tonneau cover back then reverted back to making the same noise of the pump operating but nothing moving. At this point I think all matters point to a pump that no longer builds adequate pressure as the amount of pressure to pull the cover back is much less than the pressure to lift.

Klaus sent me line guidance but I do not think he has positioning at the meter block/pump manifold either. The factory markings are present on the block bolts so I don't think they have been manipulated. I confirmed my lines were in the right position at the cylinders last night - even on the bottom, odd at the shaft end and 15 for the middle line driver side main lift cylinder.

Regarding buying a CLK55 that has a non functioning top...I'd do it again in a heartbeat. I bought it right and there is no grief here, just a guy who likes to tinker - to each their own. Thanks to all those who have come before me on these projects. The wealth of knowledge is awesome.

Rudeney

A bad pump could definitely be the issue. If you had a way to measure pressure, you could verify - it should put out be at least 170 bar. If you've opened and closed the top manually a dozen times then you should have all the air out of the system. When you hear the pump run, does it sound smooth, or do you hear any gurgling or grinding sounds? If the latter there could still be air in the system and manual open/close is the way ti purge it until the pump can build enough pressure, and then it will take a dozen cycles to completely clear it. You'll know once the pump sounds uniformly smooth in operation.

And I totally agree with you on the DIY work to fix this. It's just some parts and some wrenching and when you get it fixed, you'll have a great car.

Top Hydraulics

Hi folks,

sorry that I'm coming in late on this one. Allow me to reply to several posts below at the same time. Also, please note Top Hydraulics' DIY videos for CLK cylinder R&R (removal and replacement), pump R&R, and micro switch troubleshooting: https://www.youtube.com/playlist?lis...CemIb0SVihtBlV

Quite right. This video shows how to remove the tonneau cylinders, which includes disconnecting them on top by reaching through the trunk: The black tonneau cylinders were actually revised in 2002, and the original p/n 2098001072 was replaced by 2098001272. My records show that this started with the last six digits of the VIN being 009490, so it affected only early model years '03. Hardly any US version A209 CLK have been affected by the early, obsolete design, because the A209 was rolled out in the US quite a bit later than elsewhere.

The hoses each have a two-digit number printed on them in white or red ink, about 1/2" away from the hydraulic line fittings. There is a simple rule: the odd hose number goes on the shaft side of the cylinder (where the polished shaft comes in and out), and the even hose number always goes on the blunt end (bottom) of the cylinder. There is one cylinder with three hoses, which is the left side top drive (main lift) cylinder A209 800 07 72. It has hose number 11 on top, #15 in the middle, and #12 on the bottom. Top Hydraulics actually has stickers on the bag that we ship the main lift cylinders in, on which we clarify which hose goes where.

You can get some excellent deals on convertibles with an inoperable tops, because some convertible owners will only go to the dealer to get an estimate for fixing the top, and will be quoted an incredibly high price. In most cases, fixing an inoperable top is easy, IMHO.

Aha! Are you saying that the pump pulled the tonneau cover back a little, and then stopped moving? It takes a good amount of pressure to pull the cover for the first few inches, so I am expecting that the pump is fine. Once the tonneau cover has pulled back a bit over an inch, it hits switch S84/22. This is the switch on the left forward bracket inside the storage compartment, which indicates that the tonneau cover is in the position where the rear bow would be able to come in or out if the top were up. See our micro switch troubleshooting video at 3:54: While this switch should not have any function when you are closing the top and the tonneau cover first pulls back, the soft top controller actually registers it getting triggered and double checks whether the switch that is clamped onto the left tonneau cylinder 2098001272 is showing that the tonneau cylinder is not fully retracted any more. The latter switch is switch S84/13. It clips onto the cylinder body, and it has a slider that clips into a groove just under the rod end of the cylinder's shaft. When the shaft extends, the rider releases a micro switch on the bottom of switch assembly S84/13 and tells the computer that the cylinder is not fully retracted any more. If the soft top controller N52 does not get this signal while S84/22 is triggered, then it will stop moving the top. The pump will keep running, but the solenoids that divert fluid to the cylinders will stay closed.

MrBlackCLK55, please double check that the rider is securely clipped into place, as shown here in our tonneau cylinder removal video:
I hope this helps, please keep us posted!

Klaus

MrBlackCLK55

Thanks! As a rule out, I'll fully open & close 12 times tonight then reassess. So far I've probably done it 4 times. Each time it seems there are parts where it gives resistance at different spots. I'm guessing this is all the air being pushed out when easy, and then fluid when difficult. Those tonneau lift cylinders are a real PITA!

The pump sounds smooth in operation. I'm convinced the reservoir is going milky when operated as if it has cavitation or acts like it has lost prime. Worse case, rebuilt pump from Klaus as I don't have a way to measure the output pressure. I'll open/close several more times then place an order if needed.

MrBlackCLK55

Thanks Klaus. Switch s84/13 is new (and seated on shaft) and switch s84/22 is present and properly seated/aligned on the car.

Both switches have continuity when manually operated/tested. I'll double check the connection on both micro switches that they are in fact fully seated. It will be an absolute wrenching faux pas if all of this is the result of not fully inserting a wire connection. I'll eat crow if I have to. Let me check this evening after work. If still no-joy after checking wires and also cycling the top 8 more times manually, perhaps I'll snag a N52 online and see if this works before sending out the pump. What I perceive as cloudiness in the pump when operating still baffles me. Perhaps this is all the air being cycled that the upcoming manual operations will remove.

Rudeney

All good stuff! Thanks for chiming in Klaus - always great info!

MrBlackCLK55

Good morning all.

Klaus mentioned that when turning the car on or recently operating the pump a solenoid can energize which results in one of the tonneau lift cylinders raising while manually pushing down on the other given a blocked passage or something to this effect. Taking note, I did not turn on the key prior to opening and closing the top fully 12 times.

During these cycles - at one point when closing the tonneau cover the roof the latch mechanism self-opened as the hydraulic fluid moved through the system from manual operation causing the top to de-latch. During these cycles, there was resistance at differing stages. Might be raising the glass. A little later it might be lowering the top at the final stage as it meets the windshield. Eventually, even the tonneau lift cylinders became easy to operate and did not require manually pushing them down. It was is if a giant air bubble or hydro-lock was making its way through the system.

After the 12 cycles I looked at the pump fill tank and the fluid was ABOVE the brass plug. When I began the level was at Max. I opened to release the excess fluid. The fluid was under pressure and air was released from the expansion area as well.

Bringing the level back to "Max" and putting in operating position (lock cylinders, screw in pressure plug at base of pump) the pump ran but with the same result. Further, the fluid level dropped in the tank but there are no signs of leaking anywhere. The cylinders make a pop noise like they are ready to work but nothing actually happens. Every cylinder is dry as a bone and no leaks are evident as I chase each line (car is completely disassembled so that is an easy job). The electrical connection on the micro-switches are all snug.

I'll pull the pump just for giggles to see if one of the lines from the pump solenoids is detached. Beyond that I am now thinking about buying a used N52 and testing before sending the pump to Klaus for a rebuild. Thoughts on the logic? Where is the fluid going? The more I think about this logically it seems like a blocked passage is preventing fluid from going to a cylinder at which point it is putting back pressure of fluid and possibly air into the system.

I'll tackle the honey-do then pull the pump a little later today and inspect wires unless the World of Knowledge suggests a different course of action. Another two weeks of 30's so I have some time.

Rudeney

The fluid level in the reservoir increased? That sounds like manually operating the cylinders pushed more air into the system, which is wrong. I wonder this needs to be done with the bypass valve on the pump closed? Maybe it would be worthwhile to disconnect one line on a cylinder and operate it to make sure it is pulling fluid in? Klaus - thoughts?

MrBlackCLK55

Morning all. Correct Rudeney, it seems to be pulling air in. I saw your post and decided to do a hard stop. I concur, it should not be putting more air into the system.

When I installed by rebuilt cylinders I had an o-ring seat wrong (my error) and it was leaking fluid at the bottom of the passenger side lift cylinder. This tells me the pump is pushing fluid, but to what psi level I am not sure. I did not have a helper this weekend, but I should later this week so I can try another 12 rounds with valve closed if that becomes the consensus.

At the same time I will document the hoses and their location at my meter block and publish as a reference. Not sure if it is accurate, but it will be a starting point for another DIY to compare with and add to the knowledge pool. If two meter blocks are the same it can be added to the reference library. If different, a third will be needed to settle it. I can't believe MB does not have this on file.

If I connect with Klaus independently about air in the system I will post the details here so other CLK'ers can learn as well. I'm nearing the point of sending him the pump anyway just so I know I won't have to worry about this for a long, long time. With no interest in selling...I don't mind knowing it is better-than-new.

MrBlackCLK55

Sorry for the delay all - life got in the way of repairs. Here is the update (and thanks again to Klaus for walking me through a few things).

1) Yes, by manually operating the top too quickly the cylinders can draw in air. This was told to me by Klaus. Note to others out there. The air in the lines can make it appear that the fluid level has increased when all you have done is pressurized the fluid in the system.

2) Klaus recommended getting the top into some position of open/close then trying to complete the operation with the switch. It's a challenge but can be done. You need to reach into the storage compartment and turn the two cylinder knobs and the pump valve (having long arms will help with this task). After completing this, the top partially closed (meaning the pump appears to be working) but it would not complete its final operation (pointing to a micro switch or control module). Seeing how everything points to either the first or final step of operation I did an ohm test of the three lines to the micro switch on the lift cylinder and did not like one of them. Thinking it was a pinched wire I ran new lines (grey and grey/orange) soldered and shrink wrapped them. The ground was consistently good so I left it alone.

Prior to my electrical splicing and currently I am now stuck with a dash message "Top Operating" and the window will not fully close the final 1/4" even though the top is fully up - this is a new issue and points to an electrical problem. This presents both before and after disconnecting the battery for several hours. Upon re-energizing the system the windows will fully close but as soon as I press the top switch the message appears and the windows will not fully close. For the sake of a few bucks I have ordered a used N52 module. It is due to arrive in a about 5 days. At that point I will swap units and report back.

MrBlackCLK55

SOLVED!!!!

Closing the loop on this thread…

After soldering in a few new wires to two micro switches (I did not like the resistance levels) and replacing the N52 unit I still had the same issue.

Of note, I was still building air pressure in the pump and at times the top would be near impossible to move when manually operating. The best I can describe it is the top’s hydraulic system would seem to hydro-lock where fluid could not be returned to the pump or its movement was blocked in the meter block.

Frustrated, I ripped out the pump and sent to Klaus at Top Hydraulic as this was the last item to service. I knew I needed my cylinder’s rebuilt and figured I would work my way from inexpensive to most expensive in hopes of getting my top working. Alas, pump rebuild it was. (It’s nice to know these two items will now last the ownership of the car, and it will be interesting to see if it adds to resale down the road akin to a 996 having its IMS retrofitted.)

Upon receiving and servicing the pump Klaus found fluid contamination. The prior owner used a non-compatible fluid that hardened into a gel like substance in the pump and solenoids. Brake fluid was suspected. This prevented fluid from reaching the cylinders. After manually flushing the lines with new fluid, installing the rebuilt pump (Klaus and the Top Hydraulic team are absolutely AWESOME), I for the first time since buying the car, have a working top! And just in time for warmer days here in the north east.

Thanks to everyone out there. As always Klaus and Rudeny – you guys are a huge asset to us shade tree wrenches. I hope my learning experience helps others who purchase and make these and other drop tops function as intended. If hydro locking, you likely have a fluid and contamination issue in your pump system and meter block. Time to give Klaus’ team a call.

Safe travels.

Rudeney

Wow, what a bizarre problem! I'm glad you got it fixed. Klaus does good work!

Moto-P

As for the A209 Cabriolet, the entire set of new cylinders are $1000 rebuilt from Top Hydraulics Inc in Oregon. Former aerospace industry engineer who retired runs that business and quality is high. So that’s not too bad for repairing these tops. Pumps and hoses don’t usually fail on them, just the cylinders.

unless the canvas is all beat to hell and sunburned, it isn’t THAT bad of an investment for superb electric top down experience with full four passenger capacity. Such cars are getting rare these days.