Broken radiator neck - 1987 560 SL Benz

The neck on the radiator (which is some type of plastic - does nayone know what type of plastic?), on which the upper radiator hose attaches, has broken off leaving a little over a half inch of neck for the upper radiator hose to attach to. Short of buying/installing a new radiator I’m looking for some way to either extend the short neck, say another inch, or to enhance the grip of the hose on the existing short neck. The OD of the neck is 1.5 inches. If I can find out what type of plastic the neck is made out of could I glue a piece of similar plastic tube to it as an extender? Or should I go another route? Can I use an adhesive on the existing short neck to provide extra gripping power in addition to the hose clamp?

With only a half inch of hose fitting left, no “repair” will be reliable. It’s time for a new or salvage radiator…

I was thinking the same thing, but hesitated because I don’t think the OP is ready to give up.

Time to get another radiator.

I would go another route because glue ain’t goning to do it. It may not be reliable and it won’t be pretty, but there are solutions. Let your ingenuity be your final guide in your particular case and check these out. Both posters are living in areas where getting parts at a reasonable price might be very difficult:

I suspect you are going to need another radiator. That being the case you can try to repair this one but don’t expect success. Plastics are tough since you don’t know what plastic will bond with another and what bonding agent to use.

If it were my car I’d see if I could find some plumbing PVC pipe with an inside diameter equal to the outside diameter of the “stump” of plastic fitting remaining on the radiator. I’d clean the two mating surfaces as best I could with light sanding and alcohol or some kind of etching solution. Then I’d use PVC pipe adhesive and hopefully it would still need a little force to push to new PVC onto the stump. Then let it sit for a day or so.

Now you are going to need some more “adapters” to get the old hose onto the new PVC covered radiator. Perhaps another piece of PVC with the same OD as the original stump is available. To expect this to all hold together with hot fluid passing through it under pressure and with engine vibration is expecting a lot.

To avoid a massive blow out failure you could drill a hole and put a brass bolt through the whole mess, but this could be an area likely to leak if you do so.

If this whole idea fails then you are out the time and effort involved, but that’s about it. You’ll be buying a new or used radiator at that point anyway.

It’s all part of the Mercedes experience…It’s called Benz over…By now, BenzBoy should be well acquainted with it…

The only POSSIBLE repair would be a 1.5-1.75" PVC hose barb adapter that is a reasonably tight fit over the broken off stub. (If it won’t fit, make it fit) After cleaning up with MEK, use an industrial epoxy like J-B Weld to attach this fitting to the radiator. let it cure undisturbed for 3 days. Done properly, that SHOULD hold for a while… Perhaps a double barb fitting (a hose coupler) with one end cemented INTO the remaining stub… Explore Home Depots PVC fittings aisle…Where there is a will there is a way… I would resist the temptation to use PVC cement, which will probably not bond at all to the radiator. Epoxy, (not the 5 minute junk) will bond to a broad range of materials…