Mr. 45

I am going to change out my coolant this weekend and want to know what you did. I read the service manual and what little post's i could find. Should i use distilled water? What brand of anti freeze did you use? I think i will use plain old Prestone anti freeze unless there is some thing wrong with it. Changing it out every two year's is not a problem for me.
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Is Prestone low silicate? What will happen if i don't use a low silicate anti freeze?

TBGH

I use a low silcate antifreeze and distilled H2O. I also use DCA 4 even though the manual says that it is not necessary. I have seen block pitting and am not taking any chances.<br>John

Mr. 45

I e-mailed Prestone and this is what they had to tell me. ---<br><br>Thank you for your inquiry and your interest in our products. The Prestone Antifreeze Coolant in the Yellow Jug<br>AF-777. Is not a Low Silicate Antifreeze. Yes, ideally a Low Silicate Heavy Duty formula is best for such Diesel<br>Applications. We do however make, Prestone Heavy Duty Antifreeze Coolant. This is a blend of ethylene glycol and<br>specially formulated inhibitor package designed for heavy-Duty applications. The product is designed to eliminate the<br>need for an initial charge of supplemental coolant additives on new vehicles and recharged systems. Can be used in all<br>heavy duty vehicle applications. We hope this has been helpful. If you need additional information please let us know.<br>

phox_mulder

I would just visit the local Cummins outlet and get the Fleetguard 50/50 mix.<br>No guessing<br>No mixing<br>No questions.<br><br>Only the recomended coolant for our engines.<br><br>My .02<br><br>phox

MoParr

When I used to service diesel engines in the military, we mixed our own coolant. We used demineralized water which is even better if you can find it. Distilling water does remove some of the minerals, but not all of them. Demineralized water can be hard to find, but is even better if you can.<br> Someone else suggested the Fleetgaurd 50/50 mix. Sounds like a great idea. I bet you'll find they use demineralized water and there is no fuss.<br>

KATOOM

I got the fleetguard 50/50 mix for around $7. No messing with water ratio. And its approved by Cummins.

Big Bob

I just flushed my radiator. I refilled it with Prestone Dexcool. It is Neon Orange in color and contains no phospates, nitrites, silicates, borates or amines, and recommended changes are 5 years or 150,000 miles. I also added a bottle of Red Line Water Wetter.<br>I replaced the thermostat, it's a good thing because the rubber gasket inside the thermostat was deteriorating. <br><br>I had been having a heating problem while towing, I am almost sure the thermostat was the problem. I now run about 175 to 180 degrees around town and while I'm not towing. While pulling my 8000# trailer home from Seattle up over Snoqualamie pass at 65 MPH and never went over 195 degrees. It use to be around 215 degrees. Summer will tell the real story, but it runs about 10 to 15 degrees cooler right now. <br><br>If you haven't replaced your thermostat, I highly recommend doing so while changing the Anti-Freeze. <br><br>Just a word of caution about the 50/50 mixes. When I flushed my radiator, I removed the bottom radiator hose from the block and opened the petcock on the radiator. Flushed it several times by running water through the thermostat hole and radiator. I tried to get as much water out as possible before refilling it. I added 3 gallons of Dexcool and the Red Line Water Wetter first through the thermostat hole, then installed the thermostat. I then topped the radiator off, ran the truck to get the thermostat open, the total water I was able to add was just over 1 gallon of water total. According to my 1999 Service Manual, the cooling system holds 24 quarts, between the Dexcool, Red Line Water Wetter and water added, I only put in about 17 quarts of liquid total. What I'm trying to say is that you can't get all the water out of the block (unless there is a plug to remove on the block that I don't know about) and by filling your radiator with the 50/50 mix, the water in the block will delute your 50/50 mix and if you are in freezing temperatures you could have a problem, not to mention not having the cooling protection while driving in hot weather. <br><br>Sorry this is so long. I hope this helps some of you.

ramoszx12r

Is the Demineralized going to eat you block. For what I know it likes metal.

anoldbiker

Big Bob is right, unless your engine does not have them, you will need to pull the low point bleeds, for there will always be water in the lower portion of the block. Size of block vary and so will quality per block. I always know the total volume needed for antifreeze and put it in first, then water ... best method.

But as for demineralized water ? I was able to talk to a chemist years ago and he said water tried to pull minerals back into itself. Sort of seeks a normal level if possible. He recommends a good filtered tap water. It's clean of trash, but not to lean on normal minerals. (you don't want stuff like magnesium and calcium). If not, it will try to pull from where ever it can.

There is the question of hard water systems used in homes that should not have, but can have trace salts. Any level of salts (sodium) are not recommended for this use. So if you have a water softener, can you verify and guarantee there is no trace salt ?

It's hell trying to think @ almost 3 am.

Junk Man

Zerex G05 from NAPA? Capacity is 6 gallons. You can't get all of the coolant since there is no block drain. I just changed my heater core & flushed with a garden hose. I'm planning on filling radiator with 3 gallons of undiluted Zerex then topping off with water.

The Zerex says it is compatible with Dodge and Mercedes. The coolant threads on the diesel Mercedes forums are long enough to make your eyes glaze.