Cabriolets are such a joy to drive. For those of you who own one, you know what I am talking about. Whether called a cab, cabrio, convertible, soft-top, rag-top, drop-top, roadster, or drop-head coupe, if you have never driven in one, seek out a friend and go for a spin. I think you will know right away if you like it. Sun-roofs are convenient, targa tops are cool, T-tops are passé (remember Burt Reynolds in the black Trans Am), but cabriolets are timeless.
Although the benefits of driving a cabrio are many, they come with added costs over a hard-top car. Let’s face it, any car these days is a technological marvel, and adding a soft top that works at the touch of a button adds even more complexity, and the need for additional maintenance. As they say, “When the top goes down the price goes up.”
For close to a decade I owned a 2002 996 Cabriolet, a car I thoroughly enjoyed. The soft top always worked, reliably going up and down whenever I requested, with the little red cabrio dash light staying solidly lit, as designed, when the top was in motion. That is until about two years ago, when the top started to operate a bit slower and on occasion the cabrio light would flash when the top was in operation. I learned this was an indication that something in the roof system was not working properly.
In my defence, I did not drive the car very much, perhaps driving only 500 km each year, so I really didn’t notice the ever-slowing motion until one day, the top would not close completely. The dash light also blinked continuously when the button was pushed. Perhaps if I drove the car more frequently, I may have noticed a slowdown sooner. In any event, I finally started to pay attention one day when I really needed to close the roof as it was starting to rain. Luckily, after pushing the roof open/close button a few times, cycling the top, it fully closed. I remember at the time thinking the malfunction must have been a fluke, and that perhaps the top sensors just needed to be reset.
When I took the car for its next drive several weeks later, it was clear there was still an issue. When I tried to open the roof, the dash light flashed and the top did not fully open with the rear top cover, the part painted the same colour as the outside of the car, stuck, about 3 inches above the fully seated position, as shown in the enclosed photo. The top could be fully closed just fine, but not fully opened. A problem since it was a beautiful warm day and I needed some sun! Again, as luck would have it, cycling the top back to the fully closed position a couple of times allowed the roof to fully open. I knew I now had to find the cause of the problem, and fix it. After some research I learned there are three typical causes that impact the proper operation of the cabrio top.
First, if the car is a few years old (my car earned a check mark in this case) the hydraulic fluid in the roof pump may need to be topped up. The level can go down as components wear and even perhaps leak a small amount at connections and seals. The roof pump is used to push hydraulic fluid under pressure to actuate cylinders which rotate about pins connected to specially shaped levers which push on the metal structure of the roof to open and close it. Being low on fluid causes the pump to work harder than required, and can even lead to a pump failure, an expensive and inconvenient outcome one should do their best to avoid. Refilling the hydraulic fluid is the typical fix, provided there are no excess leaks in the system.
The second likely cause of a slow moving top is when there is actually a significant leak in the hydraulic system, most likely in the actuator itself. There are two actuators in the car, one for each side of the roof, operating in unison. Luckily for me, my car did not suffer this problem. But if you need to replace an actuator, replace both at the same time. It’s kind of like replacing the tires at the same time along any one axle. Typically this type of repair is most likely beyond the home mechanic, so seek out an experienced cabrio technician.
The third cause, and this is related specifically to when the top is being opened, is located on each side of the car. There are fabric covered trim pieces that move to cover holes that would otherwise be there when the top is fully opened. These pieces slide on vertical aluminum rails and over time, can stick. When they do not slide the full length, sensors stop the top from closing to avoid damage to the components – see the associated pictures showing the piece stuck, and properly fully closed. My car suffered from this issue. My car had two out of the three typical problems.
Follow the eight steps below to learn how to conduct the repairs I performed to my car. I believe anyone who is moderately mechanically inclined and interested in learning what makes their car’s cabrio roof function can perform this work.
Step 1: First, you should confirm whether or not the hydraulic fluid is actually low, and if so top up the reservoir. In theory, it’s no more complex to do than to top up your windshield washer fluid, but in practice a little harder to do. To start, open the cabrio top to the service position. The service position has the roof open about half-way, so the metal cover behind the rear seats is fully extended over the back of the car enabling you to reach in under the rear window and lift the back of the convertible top. You will only be able to lift the top up about 8 inches, at which point short (about 10-inch long) metal cables (one on each side of the car) need to be released from their anchors. This is done by taking a small flat-head screwdriver and gently prying under the ball head on the top end of each cable connector and pushing it off the small metal ball that it is attached to. You may be able to do this just with your finger and thumb, without using a screwdriver. Remove the top end of both cables—just the ends attached to the convertible top, not the ends attached to the car body. Once these are released, you can lift the back of the convertible top up further (rotating it towards the front of the car) and lean it against the rest of the fabric top. Use a short rope or bungee cord to hold it up, as the weight of rear window will tend to want to close the top back down. Please reference the photo above.
Step 2: You will now be looking at the parcel shelf under the rear window, which is really a moulded carpet shaped specifically to fit this area. If you have never cleaned out this area before, take the time now to vacuum the carpet as you will be removing it and do not want debris to fall down into the area below where the roof hydraulic and electric components reside. After removing any debris, locate the four plastic fabric/carpet fasteners that hold the carpet to the rear bulkhead behind the seats. They are located along the top of the back of this bulkhead. Use an interior trim tool, or you can get by with a flat-head screwdriver if you are careful. Pry out the fasteners and put them aside to be reused when you re-assemble everything.
Step 3: Lift out the parcel shelf carpet. You will need to carefully pull the carpet out of channels along rubber gaskets and under metal edges as you go around the back shelf area of car. After working your way around this entire area, lift the carpet out. Set the carpet aside to be re-installed later.
Step 4: Under the carpet area you will now be able to see some of the important components associated with making the roof work. Fastened vertically to the bulkhead is a canister, in a raw metal-silver colour, about the size of a soda can. This is the hydraulic roof pump. In fact, what you want to do is check the fluid level in the plastic reservoir mounted below the pump. Shine a small light in this area to see the hydraulic fluid level, looking for the horizontal line around the reservoir indicating the full mark. If the fluid is below this level, you need to add fluid. Of course get the proper fluid for your model and year car by seeing your favourite Porsche parts counter. You will also need a length of small diameter hose about 16 inches long, and a small plastic syringe, which you will attach to the hose and fill with hydraulic fluid, perhaps more than once (I had to fill mine three times). I went to the Home Depot to get the hose, and to the infant section at Shopper’s Drug Mart for the syringe. These items are needed to control the amount of fluid when refilling, since the reservoir does not hold very much, and the re-fill hole is in an awkward location at the bottom of the pump. See the picture below for the setup I had.
Step 5: Using the correct sized 90 degree hex-key wrench, locate the middle screw near the bottom of the pump, put some paper towels under this area in case there is any spillage, and carefully remove the screw. I had a small pair of needle-nose pliers ready to grab the screw and washer, which are both very easy to drop. With the screw and washer removed, use your hose-syringe combo (giving you another chance to re-affirm why those high-school lab classes were so important) to re-fill the reservoir with hydraulic fluid. Go slow, and be careful not to overfill. Once topped up to the full line, replace the screw and washer (be patient as this can take some time to get the thread started, which you have to rely on doing with the hex key, unless you have very long and thin fingers). And do not over tighten the screw since the pump body is aluminium and it would be very easy to strip the threads. Just snug, not too tight.
Step 6: Ensure there is nothing located to interfere with the proper operation of the roof, and give it a trial closing and opening before putting everything back together. First re-attach the two cable ball ends that were unattached in Step 1. If your car’s hydraulic fluid was low, you should see a marked improvement in speed with the top moving up and down.
Step 7: Un-attach the cable ball ends again and lift the back of the roof. Replace the rear shelf carpet, the four plastic fasteners, lower the back of the top down and reattach the cable ball ends, and you are done!
Now, if like my car, yours also has one or more sticking trim pieces as described previously as the third typical cause of a slow cabrio roof, perform the following additional step.
Step 8: Open the roof to the position where the trim pieces are facing almost vertically upward (see picture, right) so you can see the aluminum sliders they are attached to. These sliders simply need to be lubricated. I used a white spray-on grease that I bought at Canadian Tire, carefully applying the grease only to the top and bottom of the sliders. Be careful not to use too much, since when the top is fully closed, these trim pieces actually touch the face of the aluminum slider frame and you do not want grease showing on the fabric surface of these pieces.
With those steps completed, the top of my cabrio was functioning as good as new again. The total time it took me to perform all the above steps was about 2.5 hours, and that included stopping to take photos, sifting through my over-crowded shed to find the few tools I actually needed, and delays caused by the natural trepidation of doing something like this for the first time. The hydraulic fluid was the most expensive part of the repair at around $50 and it took a couple of days to come in from Porsche’s warehouse in Pennsylvania. The cost of the plastic syringe and rubber hose totalled about $6.
If your cabrio’s top is moving slowly, don’t delay. Fix it and get back to the enjoyment of carefree open-top motoring.
As always, submit your ideas for future tech articles to me at George@ONeillAdvisors.ca and even better, consider writing your own article for us to publish. Your feedback is always welcome.