New to MB.

I have green coolant in my W124 windshield washer tank. I assume it's a heat exchanger system to keep the washer fluid from freezing by warming with recirculated coolant.

I tried to pull the windshield resivior tank to drain the coolant, but instead aggravated the situation by moving the rubber plug that is probably dry-rotted and is now LEAKING the coolant from the washer tank onto my garage floor.

So, the rubber plug is shot AND I assume that there is a leak in the coolant lines that run inside the washer tank since it was nearly full of coolant (???).

I guess I need and entirely new washer tank to replace the possible leaking coolant lines AND the rubber plug that is now leaking.

Thoughts? THANKS. I have a 94' 250 D grey market wagon FWIW.

This problem is very easy to repair, the spiral tube inside the tank has a square piece in it - you will see it once you remove it, this is the thermostat for these spiral heater pipes. The end will have 2 screws, remove them to expose 2 or I think 4 O rings - replace these with new ones and reassemble it.

I had a similar problem in both my old cars - ones tank was crusted with silicated coolant deposits which looked like hard water scale, - I used hot citric acid to clean it, and after replacing the O rings, the coolant level didnt drop as often.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I think I need a new washer pump grommet to STOP the leak in the windshield resistor tank first, THEN I hope my local MB dealer has or can order these 4 O rings you speak of.

THANKS, I appreciate your time. If anyone else can add, great, please do. I'm new to MB's!

I'm headed to NAPA for heater hose, worm gear clamps, and 2 different hose couplings; ONE 5/16" to 3/8" step-down and ONE 3/8' TO 3/8" AND a 3/8" 1 foot long hose. I BYPASSED the coolant lines at the tank and never have worry about leaks or coolant/washer fluid swaps again. Bypass pic posted below. I capped off the washer fluid lines and worm clamped them too. $23 to complete. No leaks from washer tank yet and the MB dealer had one in stock! The stock grommet had tighter hole for the pump to slid into VS the original grommet that leaked when I pulled the pump off. I guess they reinvented it.

The dealer did say the 2 grommets for the thermostat on the heat exchanger COULD be ordered separatly as well as the thermostat (MB calls it a pump) also FWIW.

For future ref in this thread see below links.

OK, FOUND --------> https://www.pelicanparts.com/techarticles/Mercedes-W124/17-WATER-Windshield_Washer_Reservoir_Pumps_and_Level_Sender_Replacement/17-WATER-Windshield_Washer_Reservoir_Pumps_and_Level_Sender_Replacement.htm

ALSO:
https://www.youtube.com/watch?v=BjWBXIdYHU4

Attached Thumbnails

     

you dont need to go to the dealer for the O rings, I used some from a generic metric kit I have, the whole metal spiral thing can be removed from the tank itself, if the top cap doesnt let go, you can use a hairdryer to warm it up to release from the tank.

Quite an easy less than an hour DIY to fix this.

btw the pump grommets are easy to get, if your MB dealer cannot get you one, you can get it from a BMW and VW dealer too - cheaper I bet and they are the same part.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)