SL water infiltrations

[LunaCraze]

I get water ingress during rainfall, with droplets falling on my arm and a trickle on the back window.
Only the driver's side is problematic; the passenger side is functioning properly.
I believe I have appropriately completed the glass reset.

I can place my fingernail at the top of the glass on the passenger side.
I recently conducted another test that involved measuring with a tape from the top of the trim to the middle of the MB star on both sides.
52mm passenger, 50mm driver, both constructed from glass.
I suppose the glass is adjustable.
Capturing an accurate photograph with the camera is challenging, yet the concept is conveyed.

[Captiva]

Is this an R231? What is the mileage and age? Have you completed the roof sealing service?

[LunaCraze]

2017 model makeover, 53,000 miles.
I am unfamiliar with the concept of a roof service; however, I applied silicone oil to the seals and supported the roof during the process.

[VodScanner]

https://www.krytox.com/en/-/media/files/krytox/grease-oil-lubrication-sunroof-systems.pdf?rev=cc9a9d973fef4060bf2569eb61f0b44a

[Lemmand]

I cannot provide commentary on the R231; but, regarding the R129, when removing the door card, one may find multiple precise adjustments for the window glass position, including vertical (up/down), horizontal (back/forward), and tilt (in/out) at each clamp securing the glass's lower edge to the window regulator mechanism. If not secured enough, the glass may become misaligned; conversely, if clamped excessively, it could fracture.

The method is intricate and complex, hence it is prudent to seek assistance from an experienced individual. However, if you have already attempted to reset the closed position by pressing the keys for several seconds without success, the issue may be mechanical rather than electrical.

The door glass should not impact the rear window unless water is splashing from the side window at high speed. Do the panel gaps in the various portions of your vario roof appear correct? Could an extraneous object have infiltrated the seals, creating a gap?

My initial R129 was somewhat of a misfit, having approximately 13 prior owners; nonetheless, it was inexpensive, and I was unperturbed by the modifications made by previous individuals. The current vehicle I possess is a pristine, low-mileage, and unaltered model, which I aim to maintain in its original condition.

It may be advisable to consult an individual with extensive knowledge of the model; in their absence, it could be worthwhile to visit the SL Shop.

[Captiva]

Essentially, when I performed the task, there was a significant accumulation of dust and grit in the regions where the seals interfold. I was informed that there is no official service for the hydraulic pump itself; it is likely acceptable to use it within the warranty term, but all hydraulic fluid deteriorates over time.

I have observed online DIY methods involving the creation of an aperture in the top of the hydraulic reservoir, since drilling may risk introducing plastic debris into the tank, followed by extracting the oil with a syringe and replenishing it.

Rubber or silicone bung, task completed.

It may not be necessary for an eight-year-old vehicle, contingent upon the frequency of the roof's operation.

[LunaCraze]

Upon further investigation, the foundational measurement should be 30mm from the window edge to the door trim.
The passenger measures 25mm.
The movement is influenced by the curvature of the glass, causing it to ascend as well.

This effectively demonstrates the location of the problem.
Does not resolve the quarter pane issue; I can accept that.

[Lemmand]

I replace the ZHM fluid in my R129s biennially, to the best of my ability.

With the roof retracted and the reservoir at maximum capacity, remove the spare wheel and unscrew the filler cap. Utilise a syringe to extract as much fluid as feasible, then replenish to the level mark, which should be at maximum with the roof down and all rams fully compressed. Alternatively, record the level prior to extraction and refill to the same level. A complete fluid change is never performed; but, by conducting this maintenance biennially, I encountered no issues with the roof hydraulics over the seven years and 150,000 miles of my previous SL. I acquired my current vehicle in August 2025 and will undertake the initial fluid change this summer to assess its condition.

I was informed when acquiring my first SL that frequent fluid changes and consistent usage were the optimal methods to maintain the roof hydraulics in excellent condition. During my seven years of ownership, the hardtop was scarcely affixed to my vehicle; I utilised the car daily and maintained the roof in a retracted position almost every day, except during inclement weather. I even operated it with the roof down in winter conditions, provided the ambient temperature did not fall below 8 degrees Celsius, as stipulated in the manual to prevent damage to the plastic windows of the soft top.

[Lemmand]

Therefore, it is the rear quarter panel, not the back window?

In that instance, it may arise from the same problem.

[LunaCraze]

Primary driver's door, with a leak from the quarter lamp at the rear.

[LunaCraze]

I visited MB today, and they concur that the driver's door glass requires adjustment to prevent the quarter light from leaking.
It requires two hours for sorting.

[DaisyDrift]

This resembles a topic that our dearly missed member Television would have expounded upon with great alacrity, either here or on MBOA. A search for threads by Television on the issue may yield beneficial results.

[Captiva]

Regrettably, the 2008 SL I refer to lacks a filler cover on the reservoir, representing further regression by Mercedes-Benz.