I performed this repair this summer (7-25-02) -so far so good.


"OK I fixed it! I used JBWeld. Not a very glamorous repair but very well done.

The neck broke off in two half pieces. I glued them together with JBWeld and let them harden. I then took this assembly and glued it on to the plastic radiator neck where they came off originally.

I made sure the surfaces were VERY clean. I put JBWeld on the mating surfaces and extra both inside and outside all along where the break was.

I let these dry for about 15 hours. I attached the hose, drove through 100 degree weather with the AC on going up 6% grades. The coolant temp got up to 100 C. I feel this was a great stress test.

The repair doesn't leak and seems as hard as a rock."

http://www.peachparts.com/shopforum/tech-help/42310-help-inside-diameter-radiator-upper-outlet.html?highlight=jbweld

I used JB Weld this summer to fix the block in the 280 SE 4.5 I bought. Idiot PO (probably his kid) had overtightened the power steering belts and ruined the water pump bearing. It was "to expensive" to fix, so they just drove it home -- and put only water in the rad, not coolant. Two years later he decides to get it fixed, and it won't start, so he has it towed in, then decides to junk it.

I bought it for $50 as it, though it only needed a water pump. Ha, when I put water in it ran out of the valley, you could see the little "fountains" where the cracks were.

Dried it out, took a Dremel tool and ground a nice "V" in the cracks (three on one side, two on the other) and filled them with JB Weld.

Believe it or not, has not leaked a drop since. I was surprised, didn't think it would work that well. We shall see if it holds up under serious use -- haven't gotten the plates yet, since the cooling system wasn't the only problem.

Peter

Seems JB Weld's cult following is justified. The stuff truly does deliver what it promises.

I do think JBWeld is good stuff. As Peter pointed out, that the surface prep is critical: No oil residue or anything on the mating surfaces.

When I did the radiator outlet, I was very leery of getting a solid AND long-term solution. The failure occurred in the middle of central Oregon farmland, not a 'foreign car" let alone MBZ for miles. So far so good. Seems to have held through intense summer heat and pressures.

BTW, there is a variation of of JBWeld that is called something like JBWeld Quick, and this is not the same product. It is for lighter applications and it does dry (cure) faster. But does not have the same heat resistance or strength.

On a side note, we have an aluminum sliding door that is used frequently. The handle broke off from the mounting base. I looked all over for a replacement fit, and as the door is decades old none was to be found.

I suspected that this would be a great test of JBWeld's shear strength/resistance. I used JB to cover the two aluminum arms, forming a cover across from handle to the base. I carefully sculpted it and let it dry overnight. The handle continues to receive daily abuse and has not detached, broken or in anyway failed. I am impressed.

8 months later...
 

Eight months later, the repair is holding. I would only suggest one change:

I wrote way back when:
The copper bushing I described could probably be inserted without any adhesive at all -- that's how snugly it fits ...

I would change that to:

Definitely use JB Weld inside the radiator neck and around the outside of the copper (or other) bushing. It can slide out under pressure as the radiator neck softens under high heat.

the radiator neck of my 190e2.6 just broke this morning. Like many of you, it broke around halfway down the neck, allowing me to refit the hose to the remaining part, and refill the radiator with water.

Since this was a quick fix in a parking lot in the middle of winter, I wasn't sure that the hose would hold under normal operating coolant pressure, so I left the coolant cover in the open position, so pressure would not build up (you have to do this if you do any emergency repair on your cooling system, like taping up a leaking hose).

since my car is now 14yrs old, I figure that this was just about the time that this was supposed to happen. And I also figure that even that if the above fix holds, it may not hold for long, since other areas of the plastic parts of the radiator are probably also in the same brittle condition.

looking back, i remember that i had a regular but very gradual coolant leak that i could not trace. Maybe there was already a hairline crack in the neck by then.

My infamous attempt to repair the radiator let go this past week. The neck broke off once again, closer to the radiator with less than a 1/2 left. I noticed the residual JBWeld let go and was soft. Hmmmm.

I ended up replacing the radiator. I spoke with a radiator specialist and he said, over tightening is the number one cause of the cracking. Everyone is used to the metal tube/ radiator hose setup. He said that yes it is a very common failure.

He said as you tighten the clamp twist the radiator hose, when it stops turning, tighten about another half to full turn of the clamp, but not more.

He also said something that still sits in my mind: the clamp is not there to hold the hose on to the radiator, it is there to keep the hose from slipping off.

He suggested purposely not turning the clamp very tight at all. It is better to tighten the clamp a little more than to replace the radiator. But he also added: "I love it when everyone does over tighten them, it means business for me."

Which makes me think, anyone have the repair CD? Is there specific instructions regarding this clamp and neck?

Haasman

Ericsilver, I was wondering, would plastic PVC pipe work better than copper as it may not expand like copper to increases in heat. I am having the same problem and not looking to replace the radiator. Thanks.

Warning: This car was likely involved in at least a few smokey burnouts or "tire barking" events by way of powerbraking!! (starts down towards the bottom) Fresh engine, no word on the drivetrain....

Sorry, but felt the duty to inform my fellow Benz owners...;)

Wow, that was QUICK. GOOD job! Good LUCK to the new OWNER.

Ok, EricSilver, I just purchased a 1 1/2" long brass fitting from Home Depot and some JB Weld at Autozone and will do the repair this weekend. Keeping in mind what Haasman said about not overtightening, the hose has not given me any problems the last two days. However with my wife driving the car, I am going to do this for peace of mind. Who's to say that a new radiator wouldn't be subject to the same problem? Do they have metal sleeves? I am going to flush the radiator this weekend and finish the job.

As far as the corrosion (electrolysis) around the copper fitting- it will be a non-issue. The cooling system in your 260 is a closed system, and the reaction that takes place has self limited resource material- the coolant. AlthoughI'm not conversant in the chemistry involved, I believe the copper would also need to be in contact with a different metal for the reaction to occur. Instead, you have it surrounded by plastic.

Art

Edge,

PVC would soften and break. CPVC will withstand the heat, but it may be tough to find one that fits properly within the radiator neck. I would think the plastic-to-plastic fusion with epoxy or JB weld woul be more effective than the plastic to copper.

EricSilver, how has your fix been holding up? Maybe it's better to skip the epoxy and just use JB Weld, seeing as that part was holding up well. I am using 1 1/2" brass so even if the hose came undone, hopefully it will stay hitched and provide some coolant rather than come completely undone. Thanks.

NOTE: Post not spell checked.


Edge, (again) :)

Are you sure the fitting you bought will fit inside the neck? In my experience with Home Depot, only the 1" copper bushing fit snugly. If you can get back to Autozone or WalMart, I'd also recommend a tube of the Metal Epoxy putty.

I recommend doing this repair after the engine has been running hot for a while; the heat will help cure the JB Weld/Epoxy faster.

Be sure to take the time to thorougly clean the inside of the neck, and sand it a bit with rough sandpaper. Also sand the outside of the bushing.

Apply JB-Weld -- or the metal expoxy -- inside the neck, then on the outside of the copper bushing. Insert bushing into neck as far back as it will go, gently but firmly twisting as required. Go spend 2 to 15 hours of quality time with your wife.

After 2 hours (if you use metal epoxy) or 15 hours (if you use JB weld) the copper bushing will be pretty much permanently attached. Roll a "worm" of epoxy putty and wrap it around the exterior of the bushing, replacing the broken-away plastic. That will dry in about 2 hours, after which you can sand it down if needed.

When you reattach the hose, you can pretty much tighten it without fear of breakage. You will need to do this to compensate for the loss of the bulge on the original radiator neck which keeps the hose from sliding off under pressure. The repair will initially leak a bit at the hose connection until the rubber softens and forms a natural seal, which should occur after about 2 days of normal driving.

Let us know how it goes.