Convertible Top Motor

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jlasinski
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Joined: Mon Dec 03, 2018 12:42 pm

Convertible Top Motor

Post by jlasinski » Tue Feb 05, 2019 8:17 am

Put the top down on my 1999 C4 Cabrio for the first time since a new roof was installed prior to my purchase 3 months ago. Hit the button and it went down beautifully like it was supposed to and tucked away. Cleaned the car up and when I went to put the top up the clamshell opened and the flaps retracted as they were supposed to but the top did not raise. Could hear some clicking of solenoids from the back but that's it. When I hit the button to close it, everything retracted as it should. Read some articles and was told that the hydraulic motor is probably low on oil. I opened the back and released the valve and manually raised the top about halfway. I closed the valve and hit the switch and the top closed and latched as it should. I then tried opening it again and it went down and stowed away as it was supposed to. Ok, good, so I tried to raise it again and had the same results as before, clamshell and flaps opened but no top raise. I manually raised it again and then closed it with the switch. I think this confirms it is low on fluid but still need to check for sure. Question I have, is there a rebuild kit for the pump or does it need to be replaced or sent out to be rebuilt? Thanks, John

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5chn3ll
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Re: Convertible Top Motor

Post by 5chn3ll » Tue Feb 05, 2019 9:03 am

Check this:
http://www.cabriolethydraulics.com/pors ... aulics.php

If the issue is with blown seals inside the cabriolet top rams, this would take care of the issue.

I'd email them with your symptom description to confirm whether the rebuilt rams will resolve the issue...

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

"If you see the barrier you’ve driven into, that’s understeer. If you hear yourself hitting the barrier, it’s oversteer."
-Walter Rohrl


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5chn3ll
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Re: Convertible Top Motor

Post by 5chn3ll » Tue Feb 05, 2019 9:07 am

I like this part of their writeup:

"This method will be especially appreciated by owners of 1999-2001 Carrera 996s."

Understeer: You will hit the wall with the front end.
Oversteer: You will hit the wall with the rear end.
Horsepower: How hard you will hit the wall.
Torque: How far you will move the wall.

"If you see the barrier you’ve driven into, that’s understeer. If you hear yourself hitting the barrier, it’s oversteer."
-Walter Rohrl


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FRUNKenstein
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Re: Convertible Top Motor

Post by FRUNKenstein » Tue Feb 05, 2019 10:03 am

I bought a Mercedes SL500 project car a few years ago. I had to have all of the hydraulic cylinders rebuilt. It's not an "if" but a "when" it happens on pretty much all modern convertibles. If it went 20 years before needing to be rebuilt, that's really good. Chances are, this will be the 2nd time for your car.
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Current:
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1987 928S4 Guards Red
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Einsteiger
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Location: Overland Park, KS

Re: Convertible Top Motor

Post by Einsteiger » Tue Feb 05, 2019 12:16 pm

There is a guy in the Kansas City area that has quite a business rebuilding these hydraulics. He has people ship him cylinders for repairs from all over. Reasonable - a LOT more reasonable than any dealer - so if you are interested I can get his contact info for you. The last convertible...and I do mean LAST...had a manual top :) [1987 MB 560SL]
Kevin
"Einsteiger" - [Beginner]
1999 911 Carrera

jlasinski
Posts: 13
Joined: Mon Dec 03, 2018 12:42 pm

Re: Convertible Top Motor

Post by jlasinski » Thu Feb 07, 2019 7:09 am

Got around to opening the back and checking the fluid level. It was very low. I removed the plug and filled the reservoir and replaced the plug. what a pita! Reassembled and everything works as it should going up and down. I looked around and did not see any evidence of leakage anywhere. Not sure where the fluid would be going? Guess I will monitor it and see if I need to add again. Thanks, John

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02TX996Cab
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Re: Convertible Top Motor

Post by 02TX996Cab » Thu Feb 07, 2019 2:51 pm

Poor top operation which I *solved* by refilling the fluid in the top's hydraulic pump was my first warning sign that the seals in the rams were starting to go in my m/y 2002 Cab. No visible signs of leakage right away, but eventually the leaks became sufficiently large that some oil would leak to the ground via the drains which discharge in front of the rear tires. This is a telltale sign that the end is near.

Rebuilt rams (I got mine via tophydraulics.com) use far superior materials to the originals and are much more cost effective. I did this work over the holidays and the top rises and lowers better than new.
Proud owner of a Flat6-powered 996 Cab and 2016 GT4
Less proud owner of a Mall-Assault vehicle and (not so hot) hatch for commuting

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