Cabrio Top Hydraulic Fluid Step by Step

[Izzy]

Cabrio Top Hydraulic Fluid Step by Step

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There have a been a few occurances of the cabrio top not fully completing the cycle, or simply refusing to open or close. If the hand brake light is on, very likely it is a low hydraulic fluid condition. The work below shows step by step how to add the fluid to the system. Tools needed: 5 mm allen wrench Flat screwdriver Children medicine syringe with small hose 1 Bottle of hydraulic fluid. Porsche is the recommended, I have used John Deere below with no problems after 4 weeks of fi

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• Author
  Izzy
• Category
  Carrera (996) - Maintenance
• Submitted
  11/05/2005 10:44 AM

 

Edited February 20, 2010 by Izzy

[a1certified]

Thanks for the detailed DIY. I think I'm going to give this a try on my 2002 C4 Cab this weekend to cure its current ailment.

2 questions, though.

First, for the two retaining cable on the rear of the top, do you just yank on them to remove them or do you need a special tool/maneuver to disconnect them?

Second, where does this hydraulic fluid go if it is in fact low? Presumably it's leaking somewhere. If the reservoir is low, can I expect to see a puddle of hyraulic fluid somewhere in my car?

[Izzy]

The cables are in a ball joint, so simply push the cable part that connects to the car body (the ball) into the car, fingers ought to do it.

The fluid may decay (lower viscocity) over time, small seepage, mechanical loss due to heat and wear. I am talking over years of operation. Most hydraulic systems need replenishment, nothing mechanical will be perfect sealed.

[jmj996]

Has anyone with low fluid sucked any of the old fluid out to see what it looks like? Some of these units (like mine) are now over eight years old. I'm sure there's some point at which we're supposed to replace this fluid.

[Izzy]

John,

I have not, but if you did you would only get the reservoir fluid. The cycles are pretty short, and I can't imagine anyone opening and closing more than 5-6 times a day. Fluid should last a long time, short of getting some humidity entraped.

[spankey]

Thanks for the information but after I filler the reservior and everthing worked at first then the pump started sucking air again. Further investigation showed that the driver side hydraulic ram is leaking. Is there instructions on removing / installing the ram? Is the ram repairable or does it need to be replaced? Does anyone have a part number for the ram and an idea on the cost? The car is a 1999 cab 996.

Thanks

Spanky

[C2cab]

Thanks for the info. I am going to check my fluid this weekend. How long should it take to raise/lower the top on a 99 Cab?

[Izzy]

16-17 seconds, from my memory

[JonesnSince78]

I need to tackle this project soon. I recently bought a can of Pentosin CHF 11S to top up the power steering reservoir. On the can it is listed as a "light hydraulic oil". Any thoughts on the suitability of this fluid for use in the cabrio pump?

[apterr]

Thanks Izzy,

I will tackle this problem soon. Don't know where I would find a small syringe. Does the auto parts store sell something I can use instead? I don't see where the reservoir is in the first picture but I imagine it won't be hard to find once I have the back opened (that advice alone was great). Thank you again.

Andy T

[east996]

I also have this problem and the converstaions above made an interesting read. I would also like to find the part number for the hydraulic arm as I think mine is leaking. Please help???

[onicaloc]

I have the same problem. Except, with mine the tonneau and sides will operate, but once they are open, the top won't come up. Does that sound like the hydraulic fluid or a switch? Someone on another forum told me the e-brake switch could be bad. I've ordered a new one (they're cheap enough) but haven't received it yet. Any thoughts would be welcome.

[Izzy]

You can always find the small syringes in drug stores, these are used to measure kids liquid medicines, usually found in the same aisle as children's liquid meds.

onicaloc, sounds like you have the low fluid problem. The switch being bad will not move any part of the componetry at all.

[onicaloc]

Thanks very much for the confirm. Went by the dealer this weekend to try and get the actual Porsche fluid for it. They basically confirmed that's what it was too. The stuff from them is expensive, though. Approx. $41 for 250cl. I told them to order it, but I might not go back for it and just use the John Deere stuff you showed here.

[onicaloc]

I justed topped up my fluid. These instructions were extremely helpful. Wouldn't have had a chance without them. Thanks very much. Top is working better than before now. I actually sprung for the Porsche fluid, which was ridiculously expensive as I noted above. Not much is required, though, so I still have 3/4 of a bottle left. THose ball joins are a bit tough, especially given the space in which to work. They do ultimately just pop off though. Thanks again.

[RedCobra]

. Thanks for the good tutorial, I used these instructions on my 2000 996, and it was spot on. It seems like a daunting task in the beginning however its easy once you get into doing it. Ohh yeah that brass washer was a pain to handle.

The Porsche fluid part #000-043-204-89 incase anyone wants to use that. I used the John Deere HyGuard Fluid TY22035. It seems to have the same viscocity / texture of the porsche stuff, maybe the chemical composition is different. The porsche oil is $32 bucks for a 1/4 quart (250ml) vs the $4 for the whole quart of the Deere Stuff (definitely cheaper when you are not sure of a leak possibility). I also checked out a Mercedes convertible top fluid which is very similar to the Porsche stuff and costs $19 for the same 250ml, even the container looks the same with a different label.

[johnbruni]

thanks for all the useful info, have 02 cab that does not want to close until I give the throttle a tap. Once the RPM's of the engine are up a bit, it co-operates and closes. Do you think that could be low fluid?

jb

[HxCforLife]

Thanks for this thread it just saved me a lot of money!!! Did it last friday. Top would open about half way then start making a high pitch winding sound after reading this i got the porsche fluid and followed the steps and it works fine now thanks again!!

[99911]

This fix worked great and was easy to do. The parts guy at the local Porsche dealer confirmed that Pentosin CHF 11s is what they use for the hydrolics. I picked up a liter at the local NAPA for $22 plus tax. Only needed about 100ml, if that, to top up the reservoir. The top goes up and down like a charm now. I just bought this car less than a month ago, unfortunately in performing this fix I discoverer that the forward arm of the left side hinge for the rear tonnou cover is broken. Has anyone seen a thread on replacing that part? I figure since I already have the back carpet out I'm halfway there.

[wvicary]

Pentosin CHF 11S or Pentosin 202 can be used, I wouldn't try anything else.

[DaveFL1976]

A few points to add from a '99 Cabrio owner in Central Florida. I ran into a couple snags, and wanted to pass my info along in the hopes it'll help someone else out there, and you can plan your weekend morning accordingly.

1. Finding the Right Fluid -- Wasn't as easy as I'd hoped. I went to the two major car part store chains in my area (AutoZone and Discount/Advance Auto Parts) and didn't have any luck finding either John Deere or Pentosin fluid. Ended up going to Bennett Auto Parts (on my way to Tractor Supply, which I assumed had the John Deere) and it turned out Bennett had it and carried the Pentosin CHF 11S for $24 per liter. The Bennett dude told me that NAPA most likely carried it also, but I had no reason to check at that point.

2. Finding Something to Squirt the Fluid into a Tiny Hole -- I actually ended up using one of those poultry-basting syringes that you use to inject marinade into a chicken. I had an extra one lying around. I do recommend you remove the barbeque sauce first, though.

3. Taking Apart Your Car -- The DIY Tutoral was a huge help and I was able to make it through all the steps and make it through all the parts. Well done tutoral, so a kudos to the developer. It all worked well until my next point:

4. What to do if the Previous Owner Was a Bonehead -- After pulling the top back, removing the felt cover, and identifying the reservoir tank and filler hole, something just didn't look right. This job had apparantly been done before, because I'd noticed a few minutes before that a couple plastic trim holders were non-existant, and so too was the copper gasket/washer around the fill plug.

Okay, no problem, I'd figured. Until I tried to lefty-loosey the plug with my allen wrench. It had way too much resistance and as I tried to persuade it, I could feel the metal in the allen hole start to give way. Crap. Hit it with some WD-40, let it soak in, and try again.

Nope. It stripped the plug. And the fluid was low and causing problems with the pump, so I had to do something. How to refill this little bugger without the plug? Drill through the plug? Nope, not enough room and metal shavings would get in the resivoir. Take the tank off, refill it, and replace it? Couldn't figure out how to get in there without deconstructing the whole back of my daily driver, which I'd need the next morning for work. Take it to the dealer? Sure, if you're not up for a challenge and are made of money. I'm neither.

I decided that making a small hole at the top of the resivoir, near the fill line, would do the job. I figured that drilling a hole with a Dremel would end up forcing plastic shavings into the resivoir, which the pump may not like. I decided on heating up a nail and melting a hole in the plastic resivoir.

Filled her up, and sealed it up with a hot glue gun. (Tape's not gonna hold with the fluid, and I didn't want to go with a hard epoxy in case I need to refill. I figure a light coating of craft store hot glue, just to seal it, might do the trick.

So, to add a few parts to this DIY, you may need:

- poultry flavor injector

- finishing nail

- butane grill lighter

- hot glue gun

I'm amazed there wasn't any duct tape involved, but you should probably have some on hand, just in case.

Edited June 20, 2010 by DaveFL1976

[freakytsz]

Dear all,

hello from Belgium. and sincere thanks for the DIY tutorial.

recent owner of a 1998 carrera 996, also encountering the cab top problem.

having read this super helpful DIY and all your comments, I'm also attempting to do the same.

But I don't succeed to take the carpet off, mainly due to the 2 hard plastic bits on left and right (please refer to the attached picture)

the carpet goes around them and I don't see how I can take the carpet out without damaging the carpet in order to get it through them.

(looking at the tutorial again, the carpet in the example seems not to go around these plastic bits but with openings on the side... )

Please if you can share with me how to solve this problem it is much appreciated. (did some of you have to cut an opening?)

Thank you all in advance.

stephen

[krazyman]

The carpet just fits over this piece tightly. Remove the carpet from under the top trim piece first then slide it back from the plastic piece. It is a tight fit, but it does come off.

Jeff

[dano2512]

Great information, will tackle the job next weekend.

[james harman]

does anyone know if the 996 cabriolet top compartment lid lifting apparatus is supplied by this same reservoir? my passenger side wont lift the lid open or closed and ive manually assisted it the last two days to open and close it .