Hardtop main roof latch leaking oil

[GB1099]

I'm new to this board and hoping someone can help....I tried a search but came up empty.

I have a 2003 SL-500 and the main latch piston on roof just above rear view mirror is leaking. I pulled the headliner out and it's spurting right out of the piston seal when the roof closes. There are 2 small back hydraulic lines go into the aluminum housing….they look pressed in and I’m not sure where to disconnect them.

Does anybody have any experience with replacing this part, any idea of where to get the part (other than the dealer) or how to get it rebuilt.

I tried a company that rebuilds a lot of these on other models but they said they did not do this one yet. They were called:

Mercedes Hydraulic Cylinder Repair, LLC
Dennis Ficken
16285 S. Chester
Olathe, KS 66062


(913) 544-4521

Thanks for any help!

[okbarnett]

if you want to buy parts call Joey at Hendricks Mercedes, he gives 15%

[Lighthouse]

I can do it.

Contact me through my website Welcome to Top Hydraulics, Inc..

-Klaus

[mptolomey]

How hard was it to remove the headliner? I think my latch is also leaking...

[GB1099]

Headliner is easy to remove. Getting the actuator out is a bit more tricky. I'd cut all the tie wraps off the dual hoses as a first step. Also remember to mark which hose goes into each place on the pump in the trunk...it makes a difference. Also completely taking all the liners out of the trunk is a big help. Don't use any hydraulic fluid other than MB OEM to refill. I tried something else and the top ran really slow when weather got cold...had to drain and replace.

Good luck...it was not all that difficult.

[mptolomey]

Good to hear... I know I have the leak, I just haven't had a chance to look at the headliner yet to see if there was any "hidden" suprises in it's renewal. Any tips on the headliner to prevent damage? I have alacantara and don't want to mess it up...

[GB1099]

Mine was just the normal roof. Removed about 6 screws along the front edge and just popped it off. Took about a minute to remove. I'd take it off and wrap a towel around that actuator before it get's fluid everywhere and does more damage. Leak ruined a trim piece above the side window in my SL before I fixed it.

[Lighthouse]

Good point about using OEM fluid. You can buy the fluid at the dealer, or order the other MB approved fluid FeBi 02615 online, such as at www.autohausaz.com.

Please do not use anything but the MB approved fluid. Other hydraulic fluids have additives that are bad for the seals in your pump and in the cylinders. We have rebuilt and upgraded plenty of complete cylinder sets way before their time would have normally come, just because people tried to save a few bucks on hydraulic fluid.

There was another good remark about marking where the lines go on the pump. That's a good idea. However, you can always retrace the lines' location by matching the numbers printed on the individual lines with the matching numbers stamped on the individual ports of the pump.

Also, the hydraulic line connectors going into the pump are about 3.3 mm thick. If you have a 1/8" drill bit (3.1 mm) ready when you take out the lines, you can save yourself from excessive oil leaking out of the pump. Put the dull end of the drill bit into the open port, and that should seal well enough when there is no pressure on the line.

Folks, the removal and re-installation is a bit tedious, but no rocket science -- you can do it! The dealer would charge you lots of labor, plus hundreds of bucks for a new cylinder, when our rebuilds/upgrades cost a fraction of new cylinders, and are actually better than new. No kidding.

Top Hydraulics rebuilds all hydraulic cylinders for all Mercedes convertibles, plus BMW and Porsche. They all use the same type of seal that fails in time. These are the same type of seals that are used in R129s. The statistics on R129 show an average life of about 10 years on OEM seals. Usually, the roof latch cylinders fail first because they get warmer up there in the roof, and the aging process gets accelerated.

The seals we have developed involve a PTFE back-shell (PTFE is the chemical acronym for Polytetrafluoroethylene, which is trademarked as Teflon by DuPont). They last far longer than the original seals used by the cylinder manufacturer. Our rebuilds are actually upgrades!

Just for fun, I'm attaching some before and after photos of a rebuilt R230 roof latch piston. The photo shows a plain Polyurethane cup seal being used as replacement, as this was one of our early rebuilds.

Hope this helps,

-Klaus