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neck breaking off radiator on 1990 r129

bobby allen
Tue, 10 Dec 2019 14:19:05 GMT

Alex
Tue, 10 Dec 2019 23:33:25 GMT

Respectfully, suggest a more fuller explanation of what happened to the neck. The question as it stands suggests that you just replace the radiator, having a new neck. I don't think this is what you wanted to hear.

normajean
Wed, 11 Dec 2019 12:35:43 GMT

Agree with Alex. Attempts to repair the radiator neck will fail since no known epoxy will withstand the heat cycling of your radiator. When you buy your new one, you can epoxy a copper sleeve into the neck prior to installation as a preventive reinforcement. Just be sure to not goop it on too thickly so that it oozes into coolant passages. If you want to spend a little more to get it right, mercedesource.com offers a kit for this purpose. Nissens, a Danish company offers radiators that are, in my opinion, superior to OE. I replaced the OE in my W123 with one.

bobby allen
Thu, 12 Dec 2019 14:15:16 GMT

after research found this is common because of engineer stupidity of making radiator out of plastic spend that kinda money and get a problem like this and it aint a cheap fix anybody hear of after market one being all aluminum see there out there

Alex
Thu, 12 Dec 2019 19:57:43 GMT

Bobby, Not using punctuation probably saved you a few seconds of time when you wrote the above post, but it wasted more than a few seconds of my time because I had to read the thing more than once to understand what it meant. Chances are good that other readers of your post had the same problem. Please be reminded that the purpose of writing is for the benefit of the reader. The idea is to write in a way that makes it quick and easy for the reader to understand what the writer wants to convey. Standard English, as the international language of business, is still the best way go. So the next time you write a post in this forum, please keep us readers in mind. Thanks.

bobby allen
Fri, 13 Dec 2019 15:03:03 GMT

ok sry for my grammer , has anybody with a r 129 bought an all aluminum radiator

vince
Sat, 14 Dec 2019 12:23:52 GMT

The neck broke after 29 years. Do you expect to own the car for another 29 years? If not the original part should be fine. If you insist on something else do a search for a custom shop that fabricates radiators for race cars or custom cars.

normajean
Sat, 14 Dec 2019 19:50:27 GMT

Vince; I think the point is that if the radiator were made of aluminium or good grief brass, the neck would not have embrittled and broken off at any age.

bobby allen
Sat, 14 Dec 2019 20:09:44 GMT

ty norma jean i worked at gm and would never accept something that would cause catastrophic damage at that level btw vince i will be dust in 29 yrs

Alex
Sat, 14 Dec 2019 23:38:59 GMT

normajean has a point. My 1981 wagon with 286K miles still has the original radiator and there are no problems. Don't know what that radiator is made of, but it's not plastic.

vince
Sun, 15 Dec 2019 02:22:26 GMT

M-B went to aluminum radiators with plastic tanks with the W123 chassis so your '81 wagon does indeed have plastic tanks. I can't seem to upload an image here. Just look at the W123 cars on Bringatrailer for photos and you will see the plastic tanks. In my opinion this "complaint" is a tempest-in-a-teapot. Aluminum radiators with plastic tanks have had virtually 100% of the market since the '70s with good reason - they are a better product. As an old guy who isn't particularly romantic about the old days I don't miss all the radiator problems I had in the good old days of soldered brass radiators.

Alex
Sun, 15 Dec 2019 21:25:18 GMT

I'm with you, Vince. In the fifties and sixties I had so many problems with leaky radiators and failing hoses that I went over to air-cooled Volkswagens and a Porsche for a long time. By 1981 radiator problems seemed to subside so it was safe again to buy a car with a water-cooled engine. My 1981 wagon has a plastic overflow tank but the radiator is metal.

vince
Sun, 15 Dec 2019 23:54:51 GMT

Alex, is your cooling system set up like the 300TD in the photo (and the attached screen shot from the Parts information System)? If so, the tanks should be "plastic". The term plastic is misleading - the material is actually fiberglass reinforced nylon. The tubes and fins are aluminum. I actually know and helped the seller of the subject car - he's crazy in love with the W123. Beautiful car but it had been hit in the front early in it's life and was very, very tough to get everything back into alignment. https://bringatrailer.com/wp-content/uploads/2019/05/1985_mercedes-benz_300d_turbo_1559168688cd20849Mercedes28-1.jpg [Screen Shot 2019-12-15 at 6](//muut.com/u/mbcaforum/s3/:mbcaforum:pptS:screenshot20191215at6.38.06pm.png.jpg)

Alex
Mon, 16 Dec 2019 13:25:18 GMT

Yes, that looks like my engine.

merrill
Mon, 16 Dec 2019 14:28:02 GMT

hi, common problem with w123 series cars, half of the neck broke off my 300d. called my local radiator shop, they informed me that the replacement top of the radiators have been redesigned with a reinforced neck. I pulled my radiator and had a new top put on. took about a week and i am most likely good to go for 30 more years.

abiby
Sat, 04 Jan 2020 04:41:34 GMT

I've heard the theory that a contributing factor to the neck breaking is failing motor mounts putting added strain on the hoses/neck. Worth looking at when installing new radiator.

normajean
Sat, 04 Jan 2020 12:50:29 GMT

I'm not sure I can subscribe to that abiby. I believe the major reason for the breaks is that some of us inadvertently lean on that radiator hose neck while working under he hood.

abiby
Sat, 04 Jan 2020 15:56:06 GMT

You could well be correct, but on the off chance the theory I mentioned is a contributing factor, it would be a shame not to check them. A '96 model is well past the point that motor mounts could be failing.