Plastic Radiator Neck Failure w124
 

hello,
not a good day for me today, the plastic radiator neck cracked and i lost 1/4 of my coolant. thanks god i wasn't on a highway. the good thing that it cracked in the middle so i still have about 1/2 inch extension to put a hose on. I knew that it's a common problem with older Behr radiators and there is a kit sold here http://www.**************.com/store/item.php?item=Radiator%20Neck%20Kit to reinforce the neck with a cooper pipe. I bought this car about 3 months ago, and i actually did check the neck after i found out about this issue. Previous owner also knew about this problem and did reinforce it, unfortunately just with epoxy and no pipe, and it cracked open today...


[IMG]http://www.**************.com/alerts/alertradneck2.jpg[/IMG] (not an actual picture)


i don't have enough funds to replace a radiator, so i'm just going to install a little pipe, what is the diameter of the inner pipe of the neck? and will copper be a good choice of metal?

Over ther years, here's what I have gleened about this problem...
1) Make sure you are using the proper anti-freeze/coolant (MB or G-05).
2) Try to find a wider clamp and don't fuss with it. I swear that half the problems arise because people are loosening and tightening that clamp, and they overtighten it.
3) Make sure your motor mounts are in good shape. If your engine is rocking and rolling, it puts undo pressure on that joint.
4) Breakage is inevitable (usually around 100,000 miles and 10 years from what I've seen). Plan for it. Deal with it.

As for trying to repair it, I think I'd try to find a plastic reinforcing pipe (as its thermal coefficient of expansion will be closer to that of the radiator plastic) and use a high quality epoxy.

Sorry, I don't know what the inside diameter of the rad pipe is. When you get ready to repair it, take the broken piece to the hardware store to find a good fit. Make sure to rough up the old and new surfaces and makes sure they are absolutely clean before bonding.

Save up for a new radiator and get it replaced as soon as possible. You don't want to break down somewhere where it gets real difficult to get home. They aren't that expensive and you can do the job yourself.

Good luck!

Replacement radiators come with a reinforced neck. Check around for a used one.

andrei, instead of a temporary Rube Goldberg fix bite the bullet and replace the radiator. It will need to be replaced eventually and you'll avoid getting stranded somewhere at the worst possible time. You can buy a new Behr radiator for your 300E at benzautoparts.com for $182. Consider replacing the thermostat and be sure to use either MB coolant or Zerex G-05.

He said he did not have the funds to replace the radiator.

I think that a temporary fix should work until he has the funds for a replacement.

I think your idea might work andrei, just make sure that you get the right kind of epoxy, clean the parts, so the epoxy will hold, and let it cure.

Good luck.

When you finally get your new radiator, then do all the other things that have been suggested here.

One suggestion...have you checked wiht a dismantler yard? Maybe you can find a good used one for a little cash outlay.

I bought a new Behr a few years ago - OEM and it did not have the reinforced neck. Digging around, I leaned that Behr had stopped including the insert. That's what I was told by a couple of suppliers.

Don't be surprised if you buy a new Behr that doesn't have the reinforced neck. I'd like to believe you could still get one and I'd bet a buck you might have to buy it from an MB dealer.

Maybe someone here has a Behr source that still features the reinforced neck?

New Behr Radiators DO Have Reinforced Neck >
 

I just bought one for Phil for about $225 and the necks have the metal insert at the neck. You can buy one at the dealer for $265 if you are in a big hurry, but I got mine delivered to my door the day after I ordered it. In my case the radiator neck had not failed (it was made in 2001 - I guess a replacement for the original on my 1994 E320 Wagon) but the (steel?) clamps that hold the plastic tanks to the sides were seriously corroded and at the lower passenger side corner coolant had started to weep past. The new radiator seems to have clamps made of the same aluminum as the radiator so that should not happen again. Note that if you also replace the upper and lower hoses and buy two gallons of Mercedes coolant the total bill will run to over $310.

Nissen brand MB replacement radiators that are sold by some shops also have the reinforcing steel tube insert -

bnc

I beleive this, and another 35% are from bad motor mounts tugging at it when the engine bounces around (on a 107, that upper hose is really tight).

I fixd mine temporarily with a rubber hose inside bridging the upper hose and the inside of the neck.,till I got a replacement few months later (from the USA where parts are cheaper), Nissen brand radiator,cheaper than Behr.