Replacing radiator antifreeze in '99 ML320

My ML 320 has been off scheduled maintenance by MB for a few years now. I bring it into other places for normal oil changes, etc though. I'm wondering, living here in NY, that perhaps after 5+ years the anitfreeze might be diluting/breaking down and am thinking of either adding to it or replacing all of it.

I'd like to do this myself so can anyone tell me recommended antifreeze liquid for the ML320 and if I'd run into any problems draining/replacing? Would it be just the normal Peak/Prestone I see in department/auto stores?

Thanks, Walter

Reply to
Walter Cohen
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Zerex G5 is the AF most often recommended here for MB. I believe the Zerex container actually says it is used by MB for their new cars. I've heard the important diff is that this AF maintains better control over the PH.

Reply to
trader4

Walter, I believe Mercedes uses it's own coolant that is quite good. It looks clear like water it may be worth paying a little more. I think keeping like brand anti freeze is the best for the engine if you are doing a radiator dump and refill. I'm not being fimiliar with where the radiator petcock is on the ML. I would buy 1gal of MB coolant and make a 50% mix , you then have two gallons. Being that you are not draining the engine block, plan on this procedure on a yearly basis. Drain the radiator, then refill it letting the engine warm up temp in driveway to make shure there are not any air pockets in cooling system, drive on short road test, add coolant if nessary. This is one shade tree opinion.

Reply to
mdsimon80

I don't know if this is true for your MBZ (it is for mine, but it's 28 yrs old):

Check to see if you need to vent the system when replacing the coolant.

In the past, you would follow the hose at the top of the radiator back to the engine block. There, you'd see that it was connected to a unit called the thermostat housing cover. On the top of this cover was a plug/screw. It was the highest point in the cooling system.

You would unscrew this plug, take off the radiator cap, drain the coolant out from the bottom of the radiator, close the drain of the radiator, pour the new coolant into the radiator until it started coming out of the top of the thermostat cover, screw the plug back in, put the radiator cap back on, and fire up the engine.

Typically, the water temperature would rise up and then, well before red-lining, drop down to it's normal operating temperature. If it red-lined then either the thermostat didn't open up (and needs to be replaced) or there was air in the lines (meaning you didn't vent the engine block properly).

Replacing the coolant is something anyone should be able to do. Not venting the system when one has to is the only problem I can think of (of course, others in this newsgroup will soon enlighten me about the ones that I've missed).

You shouldn't have any trouble.

ron

Reply to
Ron Wong

I believe that according to Zerex, their G5 is used in new MB's and I think it says that on the label.

Reply to
trader4

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marlinspike

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marlinspike

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