DesertRunner

I'm new and this is my first post, sorry it is under these circumstances...

I took my R-129 2002 SL-500 into the glass shop to have a cracked windshield replaced. This is a state licensed & bonded business that I have used for other cars in the past and they usually do good work.
They had a heck of a time removing the old windshield, finally resorting to a power sabre-saw made for glass work. Even then they had to continue hand cutting the rubber sealant to get the window out. Shortly thereafter I noticed water on the floor behind the left wheel-well and also in the metal pan area that is exposed once the windshield is off (behind the firewall but in front of the dash) . Since they were spraying water when sawing and had set the water bottle down in the same area I figured it was runoff from that.

After everything was done, I left & made it about 8 miles when I noticed my radiator light come on. The temp gauge was in the middle on 80 where it usually is. Although I have never had overheating problems, we have been having 100-110 weather lately so I noted that I probably had to add some water when I got home. About a mile later I notice the gauge is between 80 and 90 and the E-brake light comes on along with the alarm. I look down and see the E-brake pedal is all wet- I also notice water bubbling up in the far left corner of where the dash meets the windshield - this quickly becomes steam coming up.
Lucky there was a gas station there so I pull in and shut it off. I got quarters and filled the radiator expansion tank and started it back up then added more water as it was taken from the tank into the radiator. (I hope I didn't do any damage putting cold water in a hot engine). The Temp Gage was again down to 80 so I took off toward home 10 miles away, put it on cruise at 55 and made it all the way home before the temp started rising again, the brake light/alarm came on again about 1 mile to home. Next morning I filled it with water after it cooled overnight.

I started it up to see where the water is coming from.... There is a hose next to the left of the blower box, with a side branch that goes up thru the firewall/windshield pan near the VIN location. This hose has a clamped connection where it goes thru the windshield pan. There is water coming out/above that connection. I can't see the back of that hose but it feels a bit rough to me. Also if water is getting inside, there must be additional leaking somewhere under the windshield in that body pan.

I have searched online for any info but find very little about it. I did find one diagram on a Russian website http://mb.ilcats.ru/part/vin/class/1.../1/language/en but even that is sketchy at best. I'm not sure I have the correct hose to begin with but their diagram calls it the "HOSE FROM ENGINE TO HEAT EXCHANGER" (A1298325594) and there is another part that it connects to that goes all the way across the pan called "HEATER UNIT WINDSHIELD HEATING; BELOW WINDSHIELD" (A1298300261).

The part numbers given are European and don't cross reference to anything I can find in the US.

I called the MB dealer (100+miles away) but all they could tell me was that I could make an appointment to bring it in.

The Glass installer at first said-"oh no we didn't do anything - but we noticed green coolant on the floor after you left"... then after he came down and looked at it he changed his tune and said well maybe we did hit something... They want to tow the car back to their shop and remove the windshield to get a look at where the water is coming from. He doesn't think he can save the new windshield so is ordering another one just in case. He did make a comment that "what if"whatever they found wasn't caused by them... I don't think that could be the case but I'm sure they will try to shift the cause if they can due to the expense this is going to incur to someone.

Neither of us have any idea what to look for (other than water leaking), if the windshield does have to come off (or is there another way to get in there), how many hoses/connections there are, where do they go, are there plastic fittings/T's, how to fix the issue or especially what part numbers to order from the dealer or from who?

Has anyone been into this area of the car or similar experience?

On another thought, should I mention this to my insurance company in case we have a dispute and they can then go after his insurance?

I don't know what I should do at this point...I'd appreciate it if anyone can help me figure this out before we start removing the windshield?

Thanks
Al (DesertRunner)

SRHsl600

Welcome to the complexity of Benz! The front glass has the heated water passage at its base. My guess the glass people cut their way into the "heated Windshield" structure.
My issues with the system is that the Mono-valve didn't work properly, but replacement stopped the extra heat to the glass during the summer. The early 600's had it as a proof of concept, and when the car had been in an ice building storm the windscreen was clear. Nice when it worked PITA when it gets cut up by someone who probable wasn't ever trained for the job!
Good luck with the repair!

DesertRunner

Thanks for that confirmation, I think you may be right. the hose I se water running from on the firewall side connects to that windshield heater (PN 129-830-02-61) and I found it sells for $205 in Phoenix. They don't indicate what it is made of however installation is probably a pricey bear. Any idea what is involved in replacing it?
Could it be as simple as un-clamping the in/out hoses and remove/replace the part or is it more complicated. (considering everything else about this car I'm betting on the latter)

Thanks

sgaar

The hose you ref in your post is #40 on the 2 diagrams.

DesertRunner

Those are the diagrams I have too. I am now thinking the Windshield Heater #150 (top diag) is what was sliced. #40 is outside the windshield pan and wouldn't provide water to inside the dash while 150 sits under the windshield and would be in a better position to supply water both inside and outside like I'm seeing.
Talking with a MB dealer tech he indicated its common for a glass shop to cut the windshield heater if they don't know its there... Windshield has to come off to diagnose and fix.

SRHsl600

Sad lesson to learn, the shop will be more careful, if they ever get another R 129 in for replacement!