OK, junior was helping Dad replace a hose, leaned over the radiator, and ... it broke. This is the connection where the line coming from the overflow tank connects to the radiator. It broke flush with the radiator. I need options. Is there a fix for this? Can I just plug the exit hole at the radiator? Is the only good fix a new radiator? Preciate 'it.

Need to know what year and model MB you have.... On a 124 gas engine the elbow is replaceable, and there was even a service bulletin to that effect.

------------------

On my 94' E280, the elbow is located on the RH side of the radiator if you are facing the car. It also broke coz' I leaned on it. Part is a small plastic elbow with a rubber o-ring. Cost me around $4.00.




------------------
94' E280 Euro
85' 300D Euro
87' 250D Euro
77' 300D Euro
Manila, Philippines

ransky,

Please reply with year and model. I saved buying a new radiator once, and may have a good trick for you.


------------------
Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

ransky,

I thought that this would be a 300D turbo. My wife had '83 300TD turbo with this connection broken when we purchased it. Someone had evidently vented the system somehow, filled the radiator and left the problem for me.

To cut to the chase, here's how I repaired it. I was very proud of myself for coming up with this solution.

I went to the custom wheel shop and purchased a custom wheel valve stem. This is basically a valve stem that you place in the wheel from the inside, and then thread a nut over the stem down to the wheel and tighten. There are, of course, rubber washers on each side.

I cut the excess part of the broken plastic nipple on the radiator down so that the hole was flush. I then took a piece of baling wire(I'm a country boy, so I use baling wire, a city person could substitute coat hanger wire) and put it through the vent hole and run it over to the filler neck. Reach in the filler neck with something and fish out the wire. Pull the wire up where you can put your valve stem on it. Don't forget the rubber washer, and put it on the wire so that it will fit in place when you pull the wire back through the hole. After correctly positioning the valve stem on the wire, bend the end of the wire so that the valve stem will not come off. Pull the wire out of the hole, mess around and get the valve stem started in the hole. Put the other rubber washer on the wire, then the nut and push them over the wire, holding the valve stem in place with the wire, while you thread the nut on the valve stem. Now push your wire back to the filler neck, fish it out again, and remove the wire completely from the radiator. Clamp your vent hose in place over the valve stem.

I ran the car several years after this poor boy repair with great success.

Good luck,

------------------
Larry Bible
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Is this the only solution to this broken overflow tube piece....mine has broken exactly the same way today as the others posted but I am wondering as to what size valve stem piece I would need and how durable of a repair this would be.

Are there any other solutions or does mercedes have a quick fix for this (I doubt it) or am I best looking at a new radiator. If a new radiator is what's needed, then do you recommend BEHR or the aftermarket (NISSENS) brand?

Has anyone tried any plumbing material such as copper fittings as a possible solution?

84 300SD 149K

__________________
1) 84 300SD 285K+ Miles (Ver Calif)
2) 84 300SD 175K+ Miles (Ver Federal)

126 300SD broken nipple on radiator to exp. tank.

1... Swear a lot!!!

2... cut and smoothed flush.

3... drilled hole (smaller than the tap)

4... 1/4" mpt tapped hole.

5... 3/8" barbX 1/4"mpt brass fitting (tough to find) with "O" ring for seal.

Larry's method is really the way to go because the wall of the radiator tank is "backed" by the flange and rubber on the inside. I'll probably redo mine using his technique tomorrow. Wish I'd known before. Mine works, but the tank wall isn't thick and the "bulkhead" effect of the tire valve seems better. Hope I can fish the wire through. Thanks, Larry.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

How about the old JBWeld cure? Possibly could be a great use if the broekn pieces are not too extensive? I have had some great results with this stuff.

The valve stem idea suggested by Larry worked great. I think it will work for anybody with a 123 or 126 plastic radiator. Here's what I did:

1. Obtain metal custom valve stem (i got mine at pep boys)..ensure it is the kind that has a metal nut and rubber washer. (Camel # 30-463 Worked for me)

2. Drill larger hole into area where overflow tube used to exit the radiator..be careful not to let plastic fragments fall inside. Make the hole carefully using smaller drillbits initially. Enlarge to diameter of valve stem

3. Obtain a piece of wire (I used a piece of 16 gauge conduit electrical wire but a coat hanger will do). Thread valve stem (with the air filling hole facing outside) - (minus the nut and outer washer. Leave the "inner" rubber washer at the base as this will be on the "inside" of the radiator and form a seal. Thread coathanger from overflow tube orifice out through the radiator top hose outlet. (You will feel the wire as it approaches the opening). Place valve stem assy onto wire and make a sharp bend in the wire so that valve stem assy will not fall off.

4. Pull wire out through orifice ensuring not to let go of other end (otherwise the valve stem might fall into radiator)

5. Using a knife or scissor, trim the remaining (outer) rubber washer so that it will sit flush against the outside opening (it comes with a slight lip/edge that needs to be trimmed). This washer will form an outer seal

6. Slip washer and nut onto wire and advance to overflow tube opening and fasten to valve stem assy. Secure

7. Remove wire

8. Attach rubber overflow tube to valve stem protruding from opening using existing hose clamp.

9. You're done!

Thanks to larry, I have managed to save replacing an otherwise good radiator!

__________________
1) 84 300SD 285K+ Miles (Ver Calif)
2) 84 300SD 175K+ Miles (Ver Federal)

I really like Larry's fix, but was unable to find the fitting he used. I opted for using a 1/8NPT X 5/16 hose nipple. Drilled the radiator overflow hole 1/64" larger dia. at a time to 11/32" and then tapped for the 1/8" NPT fitting. Roughed up the plastic and cleaned everything with brake cleaner. Used Permatex PermaOxy (1-min. set) epoxy on the threads of the fitting and screwed it in tight. Fitting is pretty stable at this point, but I too was concerned about the wall thickness of the plastic tank. I made a little "epoxy form" out of a piece of cardboard with a hole in the center and slid it over the hose nipple and made a second batch of epoxy to fill in about a 1/2" thick "wall" of epoxy outside the tank to reinforce the fitting. I have run about 400 miles with it and do not have the mushy problems with the epoxy when the engine is hot that others have described. This thing is now bulletproof compared to the stock form. Epoxy is about $4 and the fitting is another $2 - beats $200 for a radiator (of course mine isn't new either ).

Attached Thumbnails

     

__________________
1985 300TD 387k
1985 300CD (calif.) sold
1983 300D sold

You can get the custom wheel valve stem most anywhere that custom wheels are sold. I took a company vehicle to discount tire yesterday to get a flat fixed and saw these valve stems on a display board at the counter.

A follow up post since it is some seven years since I described my repair above. That repair was on my wifes station wagon which I sold to a German fellow who has an independent MB shop in Dallas. That was in about 1994. He put a new interior in the car and did a few things to it and it is his wifes car.

I saw him and the car about two years ago and she is still driving it. The valve stem is still in the radiator and has given no problems. I think this is adequate testimony that it is a sturdy repair.

Have a great day,

...and further, that the assumption of 'brittle' water necks is not necessarily worthy of radiator replacement. I know this little guy was broken from fatigue - I barely laid a hand on the hose (in cold weather) and it snapped. It's just in a convenient place to put your hand (and weight) when working on the car. The plastic nipple on the reservoir tank was already bright white at the neck from stress and had been reinforced with a brass tube by a previous mechanic.

__________________
1985 300TD 387k
1985 300CD (calif.) sold
1983 300D sold

I was replacing my water pump and was trying to loosen the alternator bolts and I leaned too hard on the overflow line from the top of the radiator to the overflow tank and broke the piece off at the radiator.

I liked the idea of the wheel valve and the threaded X barbed fitting but could not drive my car to get any parts so I improvised. I used the ferrule from a fitting like you would use to hook up an ice maker. The ferrule is .205 OD and is brass and has a flange built as part of it. I was able to hold the broken barbed piece by hand and work my way up to a 7/32" (.2185") drill bit using drill bits in 1/32" increments. Then I took the air scoop off of the radiator support so I could have access with my cordless drill and drilled the radiator with the 7/32" drill bit. Then I used a piece of hanger wire and fed it in through the hole I just drilled out and fed it to the upper hose barb on the radiator and grabbed it. Then I slid the ferrule on and put a small bend in the wire so the ferrule would not fall off.

Then I put a bit of 5 minute epoxy on the inside of the flange of the ferrule and pulled it into the radiator with the wire and pulled it up tight to the inner wall of the radiator. Then I put some more epoxy on the outside of the ferrule and slid the broken part of the radiator onto the ferrule. Then I held it for a few minutes until the epoxy set. I was worried that the hanger wire would be glued to the inside of the radiator so I used some more hanger wire and bent it flat onto itself so that I could grab the back side of the ferrule. Then I went in and had some lunch to give the epoxy some more time to set, and finished reassembling. This fix is similar to the reinforcing that is inside the outlet on the expansion tank and the primary fuel filter. I like the repair because when the hose is clamped onto the barb it is clamping on the ferrule also.

Sorry but no photos.

__________________
Doug

1987 300TD x 3
2005 E320CDI