Can anyone provide me with detailed procedure for flushing and refilling the coolant system. The only way I can see to drain the coolant is to open the drain valve on the radiator but the flow is very slow and that does not really flush the system out. I can disconnect the lower radiator hose, but again that will drain the system but not really flush anything. The hose network is fairly complicated so it is unclear where I should install a flush fitting, or if that is even appropriate on this vehicle. I would appreciate anyone who has experience with this posting a response.

Thanks,

 

OK, I found the procedure on the Benzworld forum. Thought I would post it here for future reference.

Photo DIY- Coolant Service- a la Vacuum Method
Yes, a very basic maintenance item, but one I think is overlooked, and often is POORLY and INCOMPLETELY performed.

Ask the "Stealership" *HOW* they do their $49.95 "Coolant" services...... I think you will find *MOST* will just drain the Radiator, and Refill.... end of story!
This leaves around 1/3 of the fluid still in the system. Yes, perhaps an infusion of fresh anticorrosive coolant is better than nothing,,,,, I believe in the WIS SPECIFIED method of Coolant Service as shown in this Post.

Personally I do Coolant Service every TWO years, instead of the "recommended" THREE years. I live in a horribly harsh environment of heat, humidity and salt, thus, my desire to have a more "accelerated" schedule. I also change the brake fluid ANNUALLY.

Since I do a "complete" drain frequently, I see no need to do the "Fresh Water 'FLUSH'".... Plus, I've NEVER understood the logic of how one estimates how much Straight fluid to add to compensate for the residual "Water" in the inner spaces of the engine. And, on the "modern" motors, how do you CHECK the true concentration??? All you are checking is the RESERVOIR, and NOT the actual fluid moving around IN the engine!!

Please use care when working with the coolant system. ONLY open the system with temps less than 90C, and do it SLOWLY. Wear a face shield, gloves and protective clothing.

Please Dispose of the Coolant per your LOCAL regulations, even though it is classified as "Biodegradable".

Apparently Zerex 05 is the "same" thing as the MB fluid for cheaper. WIS allow Distilled H2O. (Our water here is horrible).

I would strongly recommend the Vacuum Fill method. With the "Remote" expansion reservoirs, and their "weenie" tube with go to the radiator, it takes a long time to fill with the normal "gravity" method.. Plus you have the issue of "burping" out any retained bubbles in the system.
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Last edited by G-AMG; 05-10-2009 at 05:58 PM.

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05-10-2009, 05:34 PM #2 (permalink) G-AMG
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Date registered: Oct 2005
Vehicle: '04 G55 '80 280GE '99 S420 '98 E320 2010 E350(R.I.P) 2011 E350
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part II
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And here is another more simple method that does not fully address entrained air, but gets the job done with no special tools.

Simple Process with no special tools:

WITH A COLD/COOL ENGINE:

• drain radiator and coolant bottle
• open bleed nipples on front of engine, 1 per side, drain coolant out of there.
• change your thermostat. you may have to get the bottom bolt from below the car. here is where i tell people you cant do squat to these without a lift.
• pre mix your mb coolant and water watter to your liking. 60/40 works good, 70/30 even better, where the 30 is destilled water, the rest coolant and the water wetter just on top
• attach all your hoses and stuff back in and fill your water bottle.. some of it will immediately drain into the rest of the system but eventually stop.
• crank the car and keep filling the coolant bottle until level settles about halfway in.
• adjust as needed, check for leaks, check eng temp.
• attach cap and test drive

 

I drain coolant,and remove thermostat,and reatach fiting.Then hock up water hose and flush engine,with heater on,and motor running.Flush till water is clear.
Add antifreeze till it shows full.Then put thermostat back in.Your coolant level should be perfect.
Now if coolant was rusted bad,I'd flush.Then stopper the drain,leaving thermstat out.Our one gallon vinegar into radiator fill the rest with water and drive around.Then drain and flush the next day.

 

merc clk 3.20 coup w208 2001 year my car was in the garage for two months comes home from working out of the uk and finds all of my coolant is on the garage floor, I been told it takes a gallon of antifreeze so as the rad is us I got to change it no problem there, but how much water do I need as I going to mix it before I put it in I was thinking of a 40% antifreeze & the rest water, the coolant was in for 10 years no problem it was stable at 90c and only went up to 95c when I switch the ac off and was tested every year and gave me a reading of 25 below 0 so I left it as it and never needed to top it up.

 

I finally switched to poly gycol anti freeze at 100%,don't need to replace for 10 years.No water in system.

 

ok I will give that a good looking at