Mercedes decided to use plastic radiator tanks glued and crimped onto an aluminum core. It was light, thermally efficient, and cost effective, but the problem was in the neck of the tank. The neck was subjected to intense heat and vibration two things that plastic hates. The necks fail frequently. If you have ANY cooling system repairs done in the future no matter the mileage of your car have the tech pull the upper hose off of the neck and inspect it. If it has an aluminum insert inside of it it's OK usually. This means it has the updated tank. If not have it replaced you are ridding on borrowed time!!

All 1984 to 1994 (roughly) Mercedes.

What about aftermarket Radiators? Preferrably with aluminum sides, not the thermal plastic. I've ran into the exact problem you posted, and so far, I've seen no radiators with the aluminum inserts. I know the mounting holes (for the bottom posts) for Mercedes are the same on the 190D, and the 250D.

If there aren't any aftermarkets available, isn't it possible to buffer the radiator by using a strip of padded foam/door weather stripping where it attaches to the radiator support cross beam, and the bottom area?

Also, as a note, if you have one of these radiators, and chose not to replace it, here are some things to know.
1. The nozzle tends to break off and leave a "nub" on the radiator. In a pinch, you could re-attach the hose without leaks, but you better find a shop fast, and take it easy on the car.

2. Unless you can take the radiator apart and put it back together, you can't fix it. All known sealants, and glues (including silicone, and epoxy) will not adhere to the surface of the plastic.

3. A small peice of pipe may work, but only temporarily. Shoving a small peice of pipe in the nozzle will restrict your water flow, and build up pressure around that area. The added metal also will cause the already brittle plastic to fracture, and no amount of glue/sealant will stop water from leaking out. The pressure will just extend the fault beyond the "patch".

4. If you have a nub nozzle left, and a steam leak, take your radiator out (four clips on mine) and flip it upside down. You won't be able to close your hood fully, but enough to "latch" it. This places your leak on the low pressure side, and your water leak will be minimized, (but constant) will generally not leak steam, and will slow down a crack from spreading.

But get a replacement/in service ASAP. Temporary fixes are just that, trying to rig something usually costs more in the long run.

krystal_blade

Whats the best way to fix or replace the radiator when the neck breaks? If you replace the radiator what are the best choices? OEM, aluminum, rebuilt or just have the neck repaired? The car is a 91 400E.
PS need answer in a hurry as the car is down waiting repair.
Thanks Tom

Have you check PartsShop online service they
can UPS to you next day.
I will go for OE or OEM radiator..... because
it just make for this vehicle.

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MB STARS Master Guild Technician,12 years MB tech
5 years independent shop owner

Be sure to use an OE. Nothing else will perform as well.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SHOP MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Have suffered the same failure on my 87-SDL and 85-500 SEC, replaced the 87 with OEM, but located at a local rediator shop a solid copper and brass exavt fit replacement made for the coupe. They have them to fit all models and these units are lifetime warrented. Cooling performance is at least as good as the OEM unit with no breakage worries.

Copper core radiators are not used by car makers for many reasons; weight,lead solder, & price! Car makers don't want to be liable for the lead recycling that comes w/copper rad. & the amount of weight savings is tremendous W/plastic.

I just wish I had read this back in Dec. 1999. My 1990 300E radiator hose actually came off the neck of the radiator.

Katttfishh, If you break the neck to the radiator's upper-plastic header tank, locate a radiator repair shop that rebuilds them and have the header tank replaced. Far less expensive than buyiny a whole new radiator (obviously assuming that the rest of the radiator is in good shape). I've been through this experience already. Behr is (I believe) the manufacturer of most M-B radiators, and the Behr replacement header tank used to repair mine has a brass reinforcement sleeve inside the neck to preclude the plastic neck from ever breaking again. Enuff said ?? Hope this helps. Fred.

quote:

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Originally posted by Katttfishh:
Whats the best way to fix or replace the radiator when the neck breaks? If you replace the radiator what are the best choices? OEM, aluminum, rebuilt or just have the neck repaired? The car is a 91 400E.
PS need answer in a hurry as the car is down waiting repair.
Thanks Tom

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your local radiator repair shop should be able to replace the l/s tank,and psi test.cheaper than buying new



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