Offering cabriolet advice

Hello all! This forum, having offered such amazing help to me throughout the ownership of my 2000 Cab, I thought I'd offer some help for those in need. I have had to work on just about every single component of my 996's top and have learned a ton. Diagnosis of what component has failed and coming up with affordable fixes, can be frustrating to say the least. I have had to do the following over the course of the past few years: Replace top control unit Replace potentiometer Replace windscreen latch Have hydraulics rebuilt Replace clamshell drive If your having top issues, ask away!

Is it better to replace hydraulic or rebuild them. Mine has a leak...it’s a pain but not hard to add fluid. I have looked at some after market units for about 300 as replacements. How much is a rebuild in your experience.

Do you know the size or part number for the gasket of the hydraulic fluid reservoir on the pump? Mine appears to be leaving, but I don't see the point in sending about $1500 to replace the pump when it's just the gasket.

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I used Cabriolet Hydraulics in Bradenton, FL. $500, with shipping, for a rebuild of both hydraulics. The rebuilds come with a kit for re-installing the hydraulics including new fluid. I noticed when mine was leaking that it dripped on the tires, resulting in balancing weights falling off the rim after the fluid degraded the adhesive holding them on. https://cabriolethydraulics.com/

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My bet would be that it might be one of the screws that�s holds the lines to the pump that could be leaking. There are a few copper washers that might be an issue. Those screws are meant to be torqued to 100. You could also get a used pump on EBay for $250. (996.561.060.00)

+1 on Cabriolet Hydraulics. Sent my rams to them almost two years ago. Quick turn around and they were great to deal with.

Bookmarked for future reference. The top on my new to me 2000 C4 Cab works as it should but the last time I dropped the top it seemed to balk a bit. Got me worried. I prefer to drive any convertible w/the top down (why else would you own one?) and will only raise the top on my C4 for "security" purposes, when I leave the car unattended. It's parked in a garage at home, so no need to raise the top there. The way I look at it the more you use it, the more likely it is to break. So, I plan to use it as little as possible. I've got a manual top on my MR2 Spyder. No worries about anything breaking when lowering/raising the top on that car. Just takes a minute to do (no longer than it takes to raise/lower the top on my C4 Cab) and I'd be happier if the C4 Cab came w/a top like that too . . . but it is what it is.

I suspected my fluid was low on my 99 Cab because the motor would run, but you could hear it struggling. I added fluid and it started working again. But only for 6 months. I assume it�s leaking, but I cannot find any evidence under the car. Where could the fluid be going? I�ll haven�t been able to take the cover off and have a look.

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This is who I used, 04 C4S

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The rams usually produce a leak in front of the rear tire. That�s where my puddle was. If your drains are clogged, it may build up inside. Put the top in the service position and release the rear hold down cables. You can access the rams easily. https://cabriolethydraulics.com/diy-...-instructions/

As a DIY project how hard is it to replace the rams?

DIY based on, not lots of mechanical experience.

Ok, now I have a question. Just bought a new to me 2000 C4 Cab a couple of days ago. Apart from a glitch that seems to be related to the lock/alarm system which is now also a known problem, the roof (of course) worked fine at the showroom but have just had a couple of glitches at home in the garage. The roof still operates but it balked twice, once going down and once going up. A tug down and a tug up got it going again. The motor seems to work ok because it otherwise completes the action, locks in place and the windows go up and down as they should. I assume these glitches this mean that something is "going out" -- would that be the "rams" people have been talking about above or something else? Please advise if you can, thanks!

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Not hard at all. I posted a link to the instructions in a previous comment. One warning. Do not drop the nut that is on the far end of the ram. You will never find it.

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That�s exactly how mine acted before I had the rams rebuilt.

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Ok, thanks. Just as I suspected. Will just try to limit the use of the top. Prefer to drive only w/the top down and, unless I'm going somewhere where security is required, I'll just leave it down. Will look into rebuilding the hydraulics during the rainy season. Just looked at the Cabriolet Hydraulics website. No mention of the prices for the various options. The one I'd select is the advance ship/eturn core option. Will have to contact them about the cost for that. Also just looked at CH''s removal/install instructions which I "could do" but are at the limit of what I personally would "want to" do. Assume no Porsche dealer would install the CH cylinders. So, has anyone here ever had an indie Porsche specialty shop replace the roof cylinders and if so what the labor charge was for doing the work?

I just contacted https://cabriolethydraulics.com/ to purchase a pair of rebuilt rams. You gotta love the camaraderie of this site. Thanks for support and the information and know-how freely dispensed.

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I'd check the fluid levels in the reservoir below the hydraulic pump. If a little bit of air gets into the hydraulic ram, it will hesitate or "jump".

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It will often leak and pool in front of the rear tire. If it's a big leak, you might have a little puddle on your garage floor. If it's a small leak, you might not see it at all. If you look at the top of your hydraulic ram, and it looks real dirty, it's probably leaking.

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Ok, thanks! Don't know where the reservoir is or how to purge air from the cylinders if I do, but I'll look into it b4 I spend big $ trying to "fix" it. PS: There's also a problem w/the window on the drivers side that may or may not have something to do w/the roof. Problem is that the window sometimes will not drop and rise to fit into the edge of the roof trim, so that when you try to close the door the top edge of the window will fully or partially hit the trim making closing the door impossible or difficult I found that when the window does not retract to allow it to fit under the trim, I can push the top of the window down, after which the window will then rise into the proper position. Took the car in for a oil/filter chg and a mechanical inspection this morning and the indie shop owner speculated that there may be a problem w/the switch controlling the window. Any thoughts from you guys about this?

First thing to do is "retrain" the windows. Push the down button and when the window stops continue to hold the button for 10 seconds, then release. Do the same for up...continue to hold the up button for 10 seconds after the window stops. Second thing is the window drop is controlled by a microswitch on the door latch mechanism. Probably is going bad. Does it drop correctly when you use the inside handle? Third thing is, do you hear the motor run briefly when you expect a window drop? If so, then your regulator is bad. After time the cables stretch and the window no longer drops.

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I'd say it's a pretty easy. Swapping out my re-built cylinders took about an hour. The only part that's difficult is loosening and tightening the bolt that holds the lower end of the cylinder on. It's a tight squeeze.

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I'd say if the red top warning light isn't on, the window probably isn't related to the top. DBJoe996 has great advice about re-training the windows.

Ok, of course, the top worked fine today. No problems. 2x's up and 2x's down. However, the driver's side window is still a problem. Tried the "retrain" procedure but there was no change. Will still hit or hang on the trim/frame of the roof unless I push the top of the window down before closing the door, which doesn't help when opening the door. Was at a Porsche dealer today and spoke to a service advisor who said it's "probably" the regulator (whatever that is) and it would cost me $935 (P&L) to fix it. My indie shop guy says he's done the work before and think it's it would cost about $775. Not much of a difference. His shop is closer to me than the dealer, so I'd probably let the indie do it for that reason alone. If/when the roof balks/malfunctions again, the dealer want's $420 just to "diagnose" the problem. Will not even consider installing non-Porsche cylinders. The SA said that their typical labor charge (before parts) to work on the roof is around $1260-1680 (including the $420), which would probably make it around a $2.5-3k job. Still waiting for a quote from an indie Porsche specialty shop for the labor to take out the core (for return) and install the Cabriolet Hydraulic cylinders if the eventually becomes necessary. Prefer driving all convertibles w/the top down and I never drive any of my sports cars in the rain. So, I'm going to just keep the top down and not mess w/it any more. Hopefully, if I do this, I won't have to deal w/this problem for a LONG LONG time! The driver's side window is also NOT an issue as long as I don't put the roof up, which is another reason to just keep the top down. I also need to replace the passenger side visor (which is broken; the mirror cover is gone and the lights don't work). Another $270 (before labor) for the visor but that's not a pressing repair either and would only do it if/when I need to do the driver's side window and/or roof. As Scarlett O'Hara in Gone of the Wind liked to say: "Tomorrow is another day." LOL!

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The �stealership� always has the most entertaining prices. Even the Independent shops charge a lot for working on our precious pieces of Stuttgart engineering. I�ve found that most things on our 996s are easier to work on then you think (granted, with the right diagnosis). I�d guess the window would be the micro sensor mentioned previously. Unfortunately I�ve never had to work on the windows, so I can�t offer too much advice. For the top, if it�s working right now, I�d just use it until it has more substantial symptoms.

The top on my 2001 just stopped working suddenly. It seems to start with the back part of the car rising up to let convertible top out, but it won�t go all the way up or down without manual assistance. The convertible top light will blink when it gets stuck. i plan on checking hydraulic fluid, but was curious if that was a symptom of something else.

Just got a quote of $2632 to replace the rams in my 996 Cab from Kahlers, an indie Porsche shop in Dublin, CA. This includes parts & labor. They will not install customer supplied parts; did not know that previously. Will have to look for an indie shop that'll install the CH rams, if/when I need to get them replaced later.

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You�re probably having a �timeout� fault. This is an error in which too much time has passed between micro sensors being triggered during the course of top operation. The quickest and easiest things to check are: 1) make sure your not parked facing uphill... I know it sounds strange, but the top sometimes has a hard time working against gravity. 2) Make sure your battery is fully charged. Especially when the top has been acting up, and you�ve been cycling the top a few times to try and figure it out, the battery can loose its charge, causing the top to slow down... resulting in a �timeout� fault. 3) Check the hydraulic fluid. If all of these things are fine... now your in the weeds. A micro sensor is your most likely culprit. Diagnosing which one can be difficult to say the least.

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That�s nuts.

I would like some info regarding where are the drainages located on the cabrio and how to clean them. Thanks

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Have the "303" brand clean/protect and will apply soon. We'll see how well that clears up creases and other marks on cabriolet roof. If anyone has a better technique to make a top look like new please let us know. The top is just canvas right? If so seems we should be able to apply something like black shoe polish or some other stain to bring it back to a pure solid color. But I haven't seen any product like that or heard of someone doing it.

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I�ve used this stuff: 303 (30606) Fabric Guard,... Amazon Amazon It doesn�t restore color, but it does a good job waterproofing.

Thanks! But I hope to never need it!

Is there a preference for the expensive Porsche fluid, or Pentosin 11S or 202? And can either or both Pentosins be used in our pwr steering reservoirs? Recently with engine running and lowering and raising our top it stopped transiting (in different spots) but the motor was still turning, so I suspect fluid low even though I don't see any leaks on ground. Doubt any drains on this car are plugged it's lived in mostly dry Arizona and Cali.

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I just use Pentosin 11S... works great. Pentosin CHF 11S Synthetic Hydraulic Fluid - 1 Liter Amazon Amazon

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Sometimes the flaps on the sides get stuck...I need to tap them to get them to move....and close the top...no issues when opening the top, the issue (when it happens) is always trying to close the top....I wish there was a write up on how to dismount/clean/lubricate the mechanism for those 2 flaps

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I've found if you fold down the rear seats and take the panel off behind the seats, you have great access to those flaps and the screw drive that moves them. I've used some lithium grease on those screws and they move a lot smoother now then in the past.

Top hesitated when raising and lowering. Accessed hydraulic pump and found reservoir on minimum. Gonna purchase pry tool make it easier next time to pop cables off ball studs. 5mm allen wrench with 1' pipe extension to break loose fill port. Placed duct tape face up under bolt and washer to catch if dropped. Removed washer with one long tie strap stuck into reservoir opening and second to pry washer off reservoir housing (washer sticks from liquid friction, could leave in place but might fall down when filling). Obtained Pentosin CHF 11S from O'Reilly Auto Parts, 10 ml syringe from CVS pharmacy no charge, and taped bendable straw to syringe because couldn't find plastic hose. Would have used official Porsche fluid made by Elves in Black Forest but needed to get job done today. Took 4 syringes to bring to max, reservoir larger than it looks. Cycled top up and down works perfectly, but reservoir back below min. A second 40 ml to get up to max, cycled and this time stayed at max. Rams clean but under both black liquid residue near top. Residue dry, hmmm maybe rams overhauled already? If we have to remove them I wonder if back seat speakers can be removed to access lower nut, can't imagine reaching all the way down there with a wrench. Pristine components and wiring one of the reasons we purchased this one.

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there's a shop in tampa that sells rebuilt ones, you send your cores in and they ship back the rebuilt ones. I did this probably 4 yrs ago and have had no problems. My bill was nowhere near what you mentioned, maybe half? Can't remember, sorry

I used these guys years ago....still working well https://cabriolethydraulics.com/our-...cylinder-kits/

Dan.....I removed my top......replaced it with a new one....got the front fastened.....now it's been a while and I can't remember all the different cables & connections and where they go (old age). Is there a "step-by-step" or even better, a how-to video? Thanks, Lars in Mt. Shasta, CA

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New cloth only? Or hardware as well?

So I replaced my rams last weekend. Not too hard to be honest. Where does the fluid go when overfilling the pump reservoir? I filled it up to close to max, but after pumping more and more and more, the level never increased. So is there an overfill hole or drain somewhere?

Anyone have issues with excessive rattle in their Cab? I have a '99 and it is very noisy. My theory is that it is rattling due to loose bolts that hold the hook mechanism to the top metal structure. Similar to the issue I had with the screws that hold the sun visors in place. it seems that the metal in the top is very brittle and as a result the threads decompose over time. I fixed the sun-visor issue with nut-serts and now am thinking of using the same solution to help secure the hook mechanism.

Cloth only......everything worked as it should before I got the new top halfway on.

Dan, I replaced my top with a used top/frame. Unbolted one and bolted the new one in. Problem I'm having is when lowering the top the clam shell doesn't come back down. Stays up like a big spoiler! Putting the top up, everything seems to work as it should. Any ideas?? Driving me crazy! Thanks! Tom Oh, and everything worked fine before the swap. Canvas was worn and I found a great top for not much money. (I thought)

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sjg, I had quite a lot of rattle on mine and was advised to check where the top connects to the top of the A pillars. When driving with the window down and top up, I could press down on the top of the A pillar, and the rattle would subside. When I looked at the top, I could see no plastic "bushing" on the driver's side...passenger side was okay. Once replaced, the top was much quieter. I'm assuming your 996.1 top is the same as my 996.2.

Hi Dan! Thanks for the offer of advice. I have a 2001 cabriolet with 123K miles. I just had the hydraulic cylinders rebuilt by Cab Hydraulics but the top will not operate from the console button. They jumpered power to the pump and got it and the top to work, but no automatic operation. I know there is a control module that operates the top somewhere and there are many micro-switches. A bad microswitch would prevent even jumpered operation I would think. Any ideas where and sequence to start troubleshooting? Would a porsche testing diagnosis pinpoint problem area?

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The most likely switch might be your emergency brake position switch. As you know, the 996 requires your e-brake to be activated to initiate operation of your top. You Tube

Old thread I know but was looking to see if anyone else has had the top slip out of the retaining bow at the rear beneath the window. How does one go about tucking it back in? Is this a DIY-able job? Thanks!

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Do you have a picture?

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Yeah just took these. Thanks for looking!

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That might be repairable, but I also see that your plastic rear window is delaminating in multiple places. Once is starts, it tends to go fast, so I'd make fixing the window part of any repair you are considering. Or perhaps it's time for a new top?