ychachad

Mine in the 1995 S420 is absolutely clear. I would have thought it would be green. I think somehow my windshield fluid is getting blended with the radiator coolant, and now the whole thing is colourless. I know my windshield fluid reservoir has a leak, but can it bend with the radiatior liquids? The car is not running hotter than normal, so far. Any help would be greatly appreciated.
Y. Chachad

mbtech208

The original, factory-fill of MB coolant in some cars is blue. The rest should have an orange tint to it. I don't recommend using green coolant in any MB model, they have a tendency to cause leaks. Your coolant should be orange. If the coolant was leaking into the washer tank, the pressure of the cooling system at normal operating temperature would cause the washer tank to overflow very rapidly, losing all of your coolant and making the "low coolant" warning light come on. On top of that, you'd have a huge streaky mess when you tried to clean your windshield.

wmak8

I had a 300ce that had this problem. An aluminum coolant hose is routed into the winshield wiper reservoir in the 300ce and I had a hairline fracture in that hose. It kept setting off the coolant light on my dash but I couldn't find a leak. I did notice that my windshield wiper reservoir was filled to the top and I had never filled it. It turned out that coolant was leaking into the windshield wiper reservoir. Under higher pressure when the engine reached operating temperature or a little hotter, the crack would expand and coolant would leak into the reservoir. To fix this problem you have to replace the section of aluminum hose that goes into the reservoir. Or bypass it. I think the hose keeps your wiper fluid warm so it doesn't freeze in colder regions. Do you know if your reservoir is leaking or is it overfilled and the fluid in leaking out of the top? Check and see if your s420 has a aluminum hose/pipe going into the washer fluid reservoir. If it does, then that is probably your problem.

ychachad

Mystery solved. The MB coolant in the S420 is absolutely clear!!! I went to the dealership, and they said that clear (just a tiny tint of red) is the colour of the coolant in all Benzes since the 90s. They did a coolant test just to be sure. I also purchased a gallon of the stuff to be sure, and yes, when you do a 50/50 blend, that fluid becomes clear and transparent. The MB coolants are NOT Green, if they are green they are aftermarket, and must not be used. MB dealer said in the worst case scenario, top off with Dexcool, but never the green stuff.
Now, the liquid that drippe from my windshield washer reservoir was greenish, because I had put the turtle wax brand windshield washer fluid, which looks red/orange, but, I'll be damned, looks green once it falls on the asphalt. And all this time I thought it was the coolant.
So, mystery solved. There is no problem with the car other than the leaky windshield fluid reservoir. Thanks for all your suggetions.

PS: I think the problem started when I started adding the RainX windshield formula, which contains chemicals that MAY damage some sealant in the reservoir, thereby causing it to leak. I kept adding plain water, (no need to add WS fluid if it's going to drain) and slowly the leaking stopped. I would stay away from the Rain X and turtle wax stuff. Use the cheap blue stuff with 50 percent water.