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this is super useful. my clamshell does not go down when i open the soft top and there is an inch or 2 left, where do you think this could come from?
So either the microswitches are faulty on the flaps or they need to be calibrated because the clamshell step is waiting for them to go down before closing. Otherwise it'll just sit there.
I replaced the left cylinder due to a hydraulic fluid leak on my 2003 C4. I topped off the fluid in the pump reservoir connected the hydraulic lines then bleeding all the air out of the hydraulic system BEFORE I installed the hydraulic cylinder and installed the new cylinder leaving the top in the same "service position" as when I removed it. The top worked for a couple of cycles but then would not close fully and wouldn't open. I had to do a emergency convertible top closing as specified in the Service manual. Now top stopped working altogether. The pump is not getting turned on by the control unit. Before I can do a calibration the factory service manual says certain criteria must be met. The first two are: #1 The convertible top latch must be repaired after an emergency operation" and #2. The convertible top compartment lid drive must be repaired after an emergency operation . They reference Service no. 61 01 41 in the service manual but I apparently don't have those pages. They both were working fine fore I replaced the cylinder. Is there some mechanical initialization that needs to be performed before attempting the calibration? I read in the Bentley manual the position potentiometer must be set to 6.3Kohms I believe with the rear top cover open. But that will not even attempt to open now when depressing the open switch on the panel.
Hello gwroclaw, First at all thank you for your write up. I know is an old discussion but I was hoping you might be able to help me. I am woring on a 2003 911 where I just replaced the 2 hydraulic cylinders. After installation the top did not work and I tried to do the procedure but without the calibration portion because I do not have a durametric. Now when I activate the system to close or open it looks like is pulling only from one side and it moves unevenly. Do you think it is a matter of calibration? if so, give that I am local to NJ do you think we could try to do the calibration?
Thank you in advance for your help.
Matt
Hello gwroclaw, First at all thank you for your write up. I know is an old discussion but I was hoping you might be able to help me. I am woring on a 2003 911 where I just replaced the 2 hydraulic cylinders. After installation the top did not work and I tried to do the procedure but without the calibration portion because I do not have a durametric. Now when I activate the system to close or open it looks like is pulling only from one side and it moves unevenly. Do you think it is a matter of calibration? if so, give that I am local to NJ do you think we could try to do the calibration? Thank you in advance for your help. Matt
what is pulling on one side only? Are you talking about the rear compartment lid (aka clamshell), or are you referring to the top itself?
Hold my beer...
You must rebuild both rams at the same time, or your have the issue you're describing. Also, there may be air in the line and the pump's bleeder screw can be access from behind the right rear passenger cushion and panel. You'll need a long extension. Check out my video on this specific topic. Here I'll even share the video here, at the exact moment I discuss this:
Looking for some help folks, the clamshell is not opening.
I have read all of the posts related to top issues and they've been extremely helpful and have allowed me to get to this point.
The car in question is a 2004 911 4S Cabriolet. The LH top cylinder was leaking, that was replaced. Yes, the pot is in line with the pin on the cylinder and is in place. Prior to the repair, I did have to use the emergency open method to service the top. The latch (opens and closes) and pot (6.2) at the clamshell motor are all within spec. During repairs I found the RH flap motor faulty, that was replaced. I purchased a Durametric to calibrate the top - but it has not gone thru any cycles of opening or closing it, so I think it is just "timing out".
If the clamshell is manually opened (with a wrench), then by using the button on the dash, the top will go down, stow away, the flaps will come up, and clamshell closes . Then, again with the button on the dash, I can close the top, the flaps go down, top goes up, and clamshell closes(again ONLY if I manually open it) So I know everything is working - except the clamshell will NOT open! However, calibration will not take place and the clamshell will not open up to permit the top to open and fold into the boot. Using a test light, the motor is receiving power long enough to start to unlatch the clamshell, then power ceases. This leads me to believe something is still out of sync and the Durametric will not calibrate it. The only faults that shows up is after 5 attempts and I clear that often. There is also a fault showing in the instrument cluster, fault 9914 will not clear out. I am not sure if this is impacting the calibration?
Any help is greatly appreciated!
I also demonstrate the clamshell motor and how to test it. I believe what I had to do was manually close it and perform a few steps to get everything in sync, like rethreading the clamshell bolt and bleeding off the hydraulic pump for the top. Also, you must rebuild BOTH rams at the same time. Not one at a time. If pressure is not even you'll have issues too. This system is very finicky about everything.
I wondered if I could get advice on my convertible top issue on this thread:
I have a 2002 996 Carrera 4 convertible, and on the way back from my dealership for a " road safety check " , my convertible top would not close all the way. It stops 2 inches short of the A pillar and then tries to close the latch.
This has never happened before.
Do I need to go to the dealership to have the top re-calibrated?
Check the flaps attached the sides of the clamshell. They sometimes get in the way of it closing. You should be able to see them from your side mirrors. I'm not referring to the motorized flaps, but rather spring loaded ones that cover the gap between the clamshell and the top when it's retracted.
Did you hear the motor for the clamshell? When I calibrate the top using the durametric the clamshell opens first. If you didn’t hear the motor activate I’d guess it’s a
1) bad connection
2) the motor is broken
if you heard the motor run or the motor ran a little bit than stopped I’d look to make sure you didn’t leave the screw that goes into the potentiometer from the interior side too tight (I had similar symptoms to yours when I left it screwed all the way in). Unscrew it all way than screw-in 3 rotations.
my car is getting the IMS done right now so I can’t take pictures.
M
Sorry to resurrect this, but I went through the repair of the hydraulic rams on my '99 c4 cab sometime ago. Top has been working fine since, with one problem. The clamshell as it swings open does not swing all the way, about 95% I'd say. As the roof is lowered and stacked, and the clamshell tries to close, it does the same thing here, and closes about 95% of the way, so that it does not sit completely flush at the end of the roof lowering cycle. The light on the dash is also illuminated. Any thoughts on what may be the possible culprit? Is it a microswitch issue or maybe the clamshell drive allen screw can be used to adjust it? I'm afraid to touch it in case it triggers a need to re-calibrate.
Last edited by virtual_law; 03-17-2024 at 05:36 PM.
My guess is gunk in the sliders that are driven by the rear bowden cable mechanism. If enough gunk builds up, it can damage the clamshell hinge arms and bowden (bicycle type) cables. Just a guess though.
My guess is gunk in the sliders that are driven by the rear bowden cable mechanism. If enough gunk builds up, it can damage the clamshell hinge arms and bowden (bicycle type) cables. Just a guess though.
Thanks so much for the reply! I have followed your entire thread and videos, that's how I learnt of the emergency clamshell Allen. Those were awesome!
So I am surmising that the "alignment' with the drive pin is my problem. The sliders do appear to be gunk free on visual inspection.
In post #17 in the other thread, when you say you "aligned" the drive pin, how did you do that? By turning the Allen screw behind the motor via the rear seats? Or by moving the clamshell by hand?
When I put the roof back up, the clamshell goes back into closed position perfectly flush with body. It's only when I lower the roof that it doesn't fully retract or close.
My issue was caused by the gunk in the slider. This resulted in:
Bending the L-shaped bracket
Damaging the bowden cable drive that moves the clamshell
Braking one of the hinges.
So, for me, I had to bend the l-shaped bracket back to its normal shape in addition to the other repairs.
It looks to me as if your slider isn't all the way back. My guess is that the clamshell is hitting something, preventing it from closing all the way, and preventing the slider from going all the way back. Is the top fully folded down? Are the clamshell latches (3 of them) functioning properly? Something else binding? It's difficult to guess without seeing it.
My issue was caused by the gunk in the slider. This resulted in:
Bending the L-shaped bracket
Damaging the bowden cable drive that moves the clamshell
Braking one of the hinges.
So, for me, I had to bend the l-shaped bracket back to its normal shape in addition to the other repairs.
It looks to me as if your slider isn't all the way back. My guess is that the clamshell is hitting something, preventing it from closing all the way, and preventing the slider from going all the way back. Is the top fully folded down? Are the clamshell latches (3 of them) functioning properly? Something else binding? It's difficult to guess without seeing it.
Ohh I see. Nothing seems bent out of shape on my end so I think it's all aligned. This prompts me to look at the slider movement, which is affected as I understand by turning the screw behind the clamshell drive motor. However, since you didn't mention the screw yet, I'm not touching it. 😅
As far as my inspection goes, Bowden cable seems intact. The cables are routed neatly and don't seem to be binding.
Roof folds as normal too as far as I can tell.
Another thing that just occurred to me, when do the hinges kick in? It is after the roof is fully lowered and clamshell closes properly and hits the Microswitch right? Or are the hinges supposed to pull the clamshell down the final 5% when I lower the roof?
04-28-2023, 11:16 PM
clamshell does not go down when opening the soft top on 2000 Porsche 911
