Overflow tube broke on radiator - PeachParts Mercedes-Benz Forum

paddo · #1 12-11-2010, 07:52 PM

Is this a very obscure problem or does someone maybe have a known fix for this? Was replacing alternator today, I was in a hurry cos light running out and last dry non-freezing day for quite a while, leaning on the edge of the engine cavity or so I thought but it was the overflow hose radiator to the top-up coolant supply, and the plastic overflow tube melded with the plastic radiator broke off. Dumb mistake but in retrospect it was waiting to happen for the last 3 or 4 years.

Anyway I've just plugged it up with a screw, but thought of screwing in some sort of little brass tube that the hose could clamp to, something along the lines of a grease nipple. Maybe could actually drill out a grease nipple for the job?
I'm thinking it might not really be needed anyway and could just drive with it and the hose plugged up

PS I'll get a longer hose when I fix it so won't happen again.

1983 300SD

layback40 · #2 12-11-2010, 08:19 PM

Jam a piece of copper pipe in the hole with plenty of JBweld !!

Diesel911 · #3 12-11-2010, 10:04 PM

There is a few DIY fixes for your problem.
Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/

http://www.peachparts.com/Wikka/DoItYourSelf

While I was doing my Tubo Drain Grommet replacment I also decided to put on a longer Hose on the Radiator to decrease the chance of breaking off the Nipple.
Even with the longer Hose I believe it is still possible to lean on top of the Nipple and break it off.

babyjames · #4 12-11-2010, 10:39 PM

I found a 3cm section of tubing - brake hard line, for instance - which had the same o.d. as the i.d. on the radiator/nipple. Used a drill bit to clean the inside of the broken parts, and emory cloth on the outside of the tubing. Applied a little JB Magic to one end of the tube and pushed it into the radiator. A little more glue on the other end, slide the nipple on. Take care not to push your sleeve all the way through into the radiator. Done.

I wouldn't drive the car too far with the hole plugged. As the coolant expands it WILL find a way out. Maybe past the seals on your water pump, or a solder joint on one of the heater cores. Maybe through the wall of a heater or radiator hose. Get the point?

Jay.

69shovlhed · #5 12-11-2010, 11:17 PM

you can jury rig it w/ metal tubing and jb weld; it may last for years. or do it right and replace radiator.

vstech · #6 12-11-2010, 11:35 PM

that tube is not an overflow, it's an air vent for the coolant to the expansion tank. it's important.
I'd try one of the JB weld repairs. I've used the JB plastic repair successfully in the past. over a year and still holding.

charmalu · #7 12-12-2010, 01:11 AM

There is a thread from a few yrs back, where some one used a metal tire valve stem.

removed the upper radator hose, fished a wire from the broken nipple to the rad hose connection. then connected the wire onto the valve stem and pulled it across and into the hole. then screw on the nut and washer.
slip on the expansion tank hose and upper hose and all done.

I haven`t done this, but sounds doable.

or replace the radiator.

Charlie

paddo · #8 12-12-2010, 03:21 AM

the JBWeld (or equivalent) sounds like the easiest, and the valve stem sounds very good and maybe more reliable because it sounds like it would tend to be self-sealing from the pressure but mroe trouble of course.
Knowing me I might go for the easy one but I'll see how it pans out.
Thanks for the great collective response, guess it isn't such an obscure issue after all.
Another way to prevent it in future would be to secure the hose to the cavity wall with a bracket or two. A long hose looping down might fill with water and inhibit the gas movement perhaps, probably not though. I'm thinking its main purpose is to allow expulsion of gas that may build up in the radiator, in which case it probably isn't an urgent thing. The bigger lower hose would be the main one for coolant and pressure.

PS drove it tonight and it ran fine - hopefully charging is fixed also.

soothappens · #9 12-13-2010, 12:34 AM

Quote:

Originally Posted by charmalu

There is a thread from a few yrs back, where some one used a metal tire valve stem.

removed the upper radator hose, fished a wire from the broken nipple to the rad hose connection. then connected the wire onto the valve stem and pulled it across and into the hole. then screw on the nut and washer.
slip on the expansion tank hose and upper hose and all done.

I haven`t done this, but sounds doable.

or replace the radiator.

Charlie

Your kidding !!
My parts car the 83 300SD had that fix. I couldn't make out what it was.
After removing JB weld and bailing wire I found a valve stem.

I even took pictures. I couldn't believe what I was seeing.
So either I bought the repaired car or this is a common fix.

If I find the pics I will post them.
It Seemed to be working

On my fix I just swapped out the radiator.
Didn't want that contraption coming loose in BFE.

charmalu · #10 12-13-2010, 03:39 AM

When I replaced my new engine, I replaced the radiator with a new one even though it was doing ok at the time. Just didn`t want any problems sticking up their ugly necks.(PUN)

I was going to pull a Rad out of a SD last summer for a project. looked like a nice clean, maybe newer radiator. removed the upper hose clamp, wiggled the hose a little, and snap went the hose neck. broke like a potato chip. So maybe if the little hose nipple broke off so easy, it is time for replacement.

Iam not looking at a radiator at the moment @ 12:40am. I think there is a little wall on both sides? maybe bend a little piece of metal to cover the nipple and drill and place a screw to hold it on for protection?

Charlie

vstech · #11 12-13-2010, 08:50 AM

it's a horrid design. I TOTALLY like the 124's solution, metal vent built into the HEAD! not part of the plastic tank of the radiator!

zu! · #12 12-13-2010, 04:46 PM

Quote:

Originally Posted by charmalu

There is a thread from a few yrs back, where some one used a metal tire valve stem.

removed the upper radator hose, fished a wire from the broken nipple to the rad hose connection. then connected the wire onto the valve stem and pulled it across and into the hole. then screw on the nut and washer.
slip on the expansion tank hose and upper hose and all done.

I haven`t done this, but sounds doable.

or replace the radiator.

Charlie

Gosh! I wish I had know about this when Dan leaned on the rad and broke that very small protuberance.

I went and bought a whole new radiator for that. The cost was one thing, the sheer waste of an entirely good radiator, to me, was just, well...wasteful. This is a good trick to remember!

soothappens · #13 12-14-2010, 12:56 AM

I found the pictures.
These are minus the JB weld and all of the bailing wire.

soothappens · #14 12-14-2010, 01:00 AM

Here's a better view of the stem.

I guess it would work.
This set up would not hold pressure when I got the car.

The Gears · #15 12-14-2010, 01:10 AM

Hi Paddo.
I have saved two rads with a method I devised some years back. I can mail you the SS fitting if you like.
PM me for a set of pics of the job, its real easy. probably 20 minutes.
Found the pics

Drill of file out the broken piece to allow the fitting to fit the hole. Remove the top rad hose and fish in a coat hanger from the drilled hole. A little bend on the wire helps it go around the bend and out the rad hose neck. Grab with needle nose and pull through, easy on the rad hose nec. Could be brittle from age.

This is the fitting. A believe a tire stem has also been used by some board members but may be too large for the hose.

Slip the fitting over the wire, bent the end over to hold the fitting on the wire then pull the fitting on the wire out through the drilled hole. Slip the washer with "O" ring and nut down the wire and snug up. remove the wire back out the rad hose neck

This is the fitting installed. It is stainless steel and will fit the hose.