Hi MB gurus -

Just a quick question. My father, trying to be a good samritan, took our `90 500SL into Sears (gasp) for a coolant change. They put the green crap in it. So, when I got the car back, I scheduled a coolant flush and change at my local MB dealership. The car happened to be coming up on its 45K service, so I had it all done at the same time. However, when I got the car back, it still looks like green crap in the reservoir! Does anyone know what color is the actual Mercedes coolant (which I understand is formulated for their aluminum radiators)? Any other easy way to tell if they actually changed it out? They signed my book and everything, but I'm still suspicious...

TIA,

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Derek Lee
`63 Mercedes-Benz UNIMOG (404.115)
`64 Mercedes-Benz UNIMOG (404.114)
`80 Mercedes-Benz 300GD (W460)
`90 Mercedes-Benz 500SL (R129)
`02 Saab 9-5 Aero
`04 Toyota Land Cruiser (UZJ100)
Elk Grove, CA, USA

just off of clear. Slight yellow tint.

yea, it's a slight amber colour. If the dreaded green is still in there it should be pretty obvious...

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1993 320TE M104
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past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
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"music and women I cannot but give way to, whatever my business" -Pepys

Sounds like they drained the radiator and block, but didn't remove and drain/clean your expansion tank.

Bottom line - they didn't do a complete job.

Take it back.

And a coolant "flush" implies just that!

If all that's done is drain the old coolant and refill with MB coolant, there is still residual residing in the engine...so the green is still there.

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Mercedes Benz Antifreeze Yellow/Orange

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1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

Zerex G-05, which should be commonly available at auto parts stores is the same formulation as MB brand and is MB approved. (Read the label.)

If you have a commercial shop do the job, buy a suitable quantity of G-05 and distilled water to make a 50/50 blend and tell them to install it. The system should first be thoroughly drained (radiator AND block drains) then thoroughly flushed out with water before installing the G-05.

Duke

Do I simply flush the coolant system with water or do I purchase a coolant system flusher (like prestone)?

Thanks,
Manny

A good way to flush (engine cold and off) is to remove the heater inlet hose at the left rear of the block after the system is drained. Flushing into the nipple flushes the engine, into the hose flushes the heater core circuit. Leave the block and radiator drain valves open during this procedure. You can buy inexpensive clamps, valves, and hose at hardware stores to make up your own flush kit. The top of the radiator and engine outlet hose are tough to flush, but you can do these areas by removing the engine outlet hose from the radiator nipple.

You can also fill the system with water, start it up and bring it up to temp once or twice to hot flush the engine of the last residual old antifreeze, after you've completed engine off cold flushing.

I never recommend using any kind of commercial "flush" product - just potable water.

Duke