| Easy to remove & rebuild ALL R129 Hydraulic Cylinders on MY90
Hi Guys
I'm very new to this forum but already it has helped me enormously, especially in regard to the above. The majority of my convertible top hydraulic cylinders were leaking on my 90 model 500SL.
When I approached two very experienced MB specialists here in Sydney both of them shook their heads and looked in horror. Partly more from ignorance I suspect and fear of the unknown; not a common problem here it seems.
They both priced all new cylinders with MB and came back with job totals of approx $10,000 - $12,000 (one third of the cars value).
Well I said the proverbial 'F... That' and started searching; and here I am.
If anyone is worried about tackling this job, don't be. I'm no trained mechanic but reasonably handy and i really did not find it that hard. All the info is here on this site in the ultimate convertibel top hydraulic thread.
With out going into great detail, the most important thing I found was to have the roof in the half open position with the front edge of the roof pointing vertically straight up. Once you have removed a few cylinders use a stretchy strap with a couple of hooks either end to hold the roof in this position.This allows plenty of room to get to the cylinders in the soft top storage area. Prior to that the removal of the rear seats and interior trim was also easy.
Even though all the hydraulic lines and cylinders are number matched it is a good idea to mark everything with sticky tape tags.
One thing i did not find on the site is how the hydraulic line clips come off - they just slide / pull off either vertically or straight down in line with the cylinder. use a pair of needle nose pliers.
The most difficlut cylinders were the small ones that actuate the roof frame itself, these sit in the same vicinity as the two main roof actuation cylinders.
They are in amongst the framework of the roof and the lines, top pin and base bolt are more difficult to remove than all the others.
The trick is to keep moving the soft top (with a helper) until the bottom securing bolt lines up with a hole in the metalwork inside the car on the B pillar. Once this bolt is removed the top of the unit can be manipulated again while moving the roof around, then the lines and top pin can be accessed reasonably easily. Take off the polished metal 'flap' and bracket that folds back when the top opens and closes, there are two phillips heads screws holding it to the top of the B pillar.
For the main soft top cylinders the only unclear bit was where the two bottom mounting bolts are. They were hidden by the wiring harness very low down to the floor at the bottom of the B pillar. Just manipulate the harness aside while you get to them.
While removing all cylinders i numbered each one and kept a list noting its location and side of the car it was attached to. I used a home engraver to engrave the number 1 through 12 on all the cyliners. Permanent marker is no good, the cylinders will have fluid on them and it will wipe straight off - no matter how well you think you wiped the cylinder.
Some of the cylinders were encased in metal brackets, i left the following cylinders attached to their metal brackets and shipped them as is, mainly for fear of damage upon removal:
- Both windscreen release cylinders
- Both storage area lid release cylinders (mounted vertically inside the soft top storage area-most accessible of all cylinders)
All other cylinders were either not encased inside a metal bracket of some sort of were easily removable.
I also took photos when i removed cylinders from metal brackets to show their orientation for re-assembly.
All 12 items were then wrapped carefully and boxed up and sent to Dennis Ficken in the US (details on this site), Dennis quoted $40 each for repair.
For the Aussies here i got DHL to ship from Sydney to Kansas for $225 AUD on a 3-4 day service. The final package weighed 6 kilograms and used a DHL Junior Jumbo box.
If you take anything away from this thread, it has to be JUST HAVE A GO.
IT IS NOT A HARD JOB - SO FAR AT LEAST.
You will save yourself a bunch of money and frustration, I wasted weeks while the MB specialists worried about how hard this job might be. Not one of them bothered to do some research like getting on this site. They just had a too hard attitude and complained that with the cylinders going to the US the car would be taking up space in the workshop for too long.
JUST DO IT YOURSELF!! and enjoy your car rather than wanting to burn it when some guy tells you it's going to cost near what the cars worth to fix it.
I hope this has given some useful tips and i'll update everyone when the jobs finished. | 
Linear Mode
