My coolant expansion tank suddenly cracked and I could not find the OEM that was readily available, I was able to locate one that fits all other W126 chassis and because my wife uses the car daily and relies upon it, I decided to attempt a retrofit using a tank that is for a 300SD. As you may well know, the 300sdl model was produced only fro 2 years, 1986 - 1987 and vehicle specific parts are not only hard to come by but also very expensive...... Here are pictures of my retrofit, the cooling system is operating like a charm!

Attached Thumbnails

 

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Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

Too bad it has green coolant in it.

Zerex G-05 is what's required.

Forgive my ignorance but what is the difference?

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

The chemistry of the coolant.

Zerex G05 is what the dealer sold and used up until about 1 year ago. It's yellow in color. It's a HOAT coolant with Nitrides to prevent cavitation in diesel engine water jackets. The chemistry between green and G05 is totally different. In order to protect the engine, radiator, and plastic components of the system, you should flush all the green coolant out and refill with 50/50 distilled water and Zerex G05. You can get it at Orielly's or Napa.

Amazon also sells g-05 if there is no local stores near you. FYI Napa has the undiluted, full strength coolant, which is cheaper than Amazon. No idea Orielly's had it.

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Nosce Te Ipsum "Know thyself"

Yep. Orielly's usually keeps 1 or 2 jugs in the back. You have to ask for it. Personally, I call the closest store to me, describe the product and ask if they have some. Usually they check the inventory and if they say yes I just ask if they can go to the back and verify that it's there. If it is, I fly over in 5 minutes and pick it up. Usually between 16-18 bucks for a gallon of undiluted. Distilled water is 88 cents at Walmart. It never fails to strike up conversation when people see me wheeling a cart full of distilled water to the cashier. It tastes gross, so they wonder what I'm doing since I'm not drinking it. The G05 may be a bit more expensive than plain green, but it's good for 5 years instead of 3 and it will prevent headaches like cracking plastics and corrosion of the cooling system.

Specifically electrolytic assault on the inside of the heater core of some of our cars... and that is the worst thing to have to replace.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

After doing the heater core on my car about a year ago, I'll spend $50 on a jug of coolant if it means I never have to do it again. Ugh. Miserable job.

First off, great discovery. I had a similar experience, trying to find a reasonably priced replacement for the tank in my (one year only) 190DT. Turned out, the tank from an E400 gasser is exactly the same in every respect except price. Mercedes seems to design the same tank over and over, giving it new part numbers for each car.

As for green vs yellow coolant. I changed to G05, just in case I ever had to post a picture here. The noise just overwhelms the thread. FWIW, each nationality seems to have it's own prejudice with regard to anti-freeze corrosion inhibitors. In germany low silicate, in japan no phosphates, in the US no silicates at all or high silicate, depending on now or then. Green usually means traditional silicate inhibited antifreeze, which is perfectly fine for "our cars", or perhaps I should say that it was always fine for my cars until I started showing photos on the web. The only interesting thing G05 adds is a bit of nitrite inhibitor to prevent cylinder cavitation, but I've never heard of this sort of damage in a benz. G05 is also includes silicates, which is why it's HOAT, as opposed to Dexcool which is pure OAT. The reason Mercedes specs it is that the inhibitor package includes stuff for both gas and diesel engines, so they only need to keep one thing on the shelf. And because it's hybrid OAT, they claim it has a long change interval. The green stuff needs to be changed every two-three years.

Changing antifreeze types is tricky, as the inhibitors don't always play well together. if you decide you've had enough ridicule and want to go G05, do several plain water flushes before you refill.

IMHO if MB wanted green coolant they'd spec it. They didn't, so there's a reason. Occam's razor.

MxFrank, thanks for thinking outside of the box, Mercedes Benz is sometimes so full of crap that it turns my stomach. People act like it's some kind of cult or religion that you dare not question. I've done so many modifications to my Mercedes over the years that it's not funny. It's just a car.... I've owned over 50 and currently have 4..... I've made my own wiring harnesses, all kinds of stuff...... Guess that makes me a sinner..... but my money stays in my pocket!

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

Other great place to get the Zerex is Zoro Tools. Search for a coupon and you can get them for about $10 a gallon if you buy multiples.

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.

Basic chemistry isn't a cult. MB used certain plastics in their products, and they specified a certain coolant for that reason. You can use whatever coolant you wish (hell, 100% water cools even better than 50/50, you should just use that!) in your own car but we're all here to tell you what's best. You don't think it's ironic that the reason for your tank replacement was that the original cracked? Now that we're telling you green coolant causes that, you choose to dismiss it.

I know it's now been a while, but can the original poster, or anyone else who has tried that retrofit share with me whether, as I think I've now deduced (after buying all of the supplies), that you need to take out the windshield wiper reservoir (permanently - as in lose the use of it) in order for the coolant reservoir shown to fit? If so that really takes some of the luster of off it in my opinion. Thanks.

I have a 350SD; your pic looks like its bottle iirc; or, is it moved further back?

Regarding G-05; there is an improvement.

MB has done away with G-05 on its bevo sheets. It has replaced it with G-48 (BMW blue), which is effectively G-05 with 2-EH, an organic acid that has been known to harm some rubber components and silicones (recall Dex-cool issues in late 1990s GM V6 engines).

John Deere Cool-Gard was essentially (though not exactly) G-05. They have improved upon the formula for use in mixed metal engines, including being nitrite free (nitrite damages aluminum), 2-EH free, etc. John Deere Cool-Gard II is fully compatible with Cool-Gard and G-05 (unlike green, all-makes OAT and HD ELC OAT coolants). It is the best bet especially for mixed metal OM603 engines, IMO, and likely also for the 61x engines.

This is a good thread that has a detailed conversation with a JD engineer quoted in it:
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1696012

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)