Help! I need a nut (85 300TD) - PeachParts Mercedes-Benz Forum

Douglas.Sherida · #1 04-10-2007, 05:26 PM

I'm desperate.

At some point in the past a PO's mechanic left off a nut duing a repair and now I'm stuck.

Its one of the nuts (and washers?) at the base of the radiator that threads over the nipple that the transmission cooler lines connect to. It is a large diameter (24mm OD hex with an M16 ID thread? - the thread is the same as the transmission cooler line), but thin, nut that pulls the transmission cooling radiator (inside the main radiator body) out against the main radiator body, thereby sealing the radiator. I can't tell it is has an accompanying washer or if the nut itself is flanged, by looking at the other side. Its been missing for years, but this past weekend the accumulated grime that had miraculously kept the radiator sealed finally let go. If I push the transmission cooler line forward (into the radiator) all the coolant leaks out (and it has), but if I pull it backward (toward the engine) it seals to a slow drip (but is not drivable).

If anyone can pull this nut off another car and send fedex it to me by Friday (so I can fix it by Saturday), you'll not only have my eternal gratitude but $20.00 in your PayPal account. It's more than worth it to me, and I just don't have the time, or transportation, to get to a junkyard and get one myself.

I'm near New Haven, CT.

You can contact me directly by adding: n@gmail.com to my forum user name

Thanks,

Doug

rrgrassi · #2 04-10-2007, 05:32 PM

Sounds like you may need the entire line. I have not had mine apart so I do not know if it is just a nut or if it is a compression type fitting.

Douglas.Sherida · #3 04-10-2007, 05:42 PM

Quote:

Originally Posted by rrgrassi

Sounds like you may need the entire line. I have not had mine apart so I do not know if it is just a nut or if it is a compression type fitting.

Let me clarify, the nut is on the radiator not the transmission cooler line hose. It threads over the same fitting that the hose attaches to.

Thanks for the reply though.

Douglas.Sherida · #4 04-11-2007, 09:19 AM

bump.

Last chance to help out a desperate fellow diesel head.

If not, I'll be ordering a new radiator today for almost $300.

I know its a better way to do the repair, but with the amount of rust on the car I'm only looking to extend its life a few more years (the kid is going to college in the fall).

tobybul · #5 04-11-2007, 09:29 AM

Hi, I have this aftermarket radiator in my 84D and it works well. Check this link and ask them where you can get them. Last time I checked they are even much less than the regular aftermarkets. When you order them, just make sure that a drain/petcock comes with it.

http://www.csfimports.com/home.asp

vstech · #6 04-11-2007, 09:34 AM

where do you live? are there any junk yards near you?
I have a cracked radiator from my SD, I can pull the parts off it for you.
John

tobybul · #7 04-11-2007, 09:37 AM

http://www.radiatorexpress.com/part_lookup.asp

Found this place online around $200 or less

Douglas.Sherida · #8 04-11-2007, 10:29 AM

Quote:

Originally Posted by vstech

where do you live? are there any junk yards near you?
I have a cracked radiator from my SD, I can pull the parts off it for you.
John

John,

PM sent

Toby,

Thanks for the link, I'll probably be putting in an new radiator next weekend when replacing the nut fails to seal it.

dmorrison · #9 04-11-2007, 12:25 PM

Afraid your out of luck.
To my knowledge the receiving assembly, which is what your talking about is a part of the radiator that is attached while the bottom plastic and aluminum sections are apart. Every radiator I have ever installed. Those parts come already installed in the radiator. Either glued to the plastic or attached from the inside. The hose has the attaching "nut" and the segment on the radiator is for tightening only.
If you can attach another unit please post it so others will know. But again I thought the unit was installed at the factory and not a serviceable part.

Dave

vstech · #10 04-11-2007, 12:30 PM

well, I will take pictures of mine, and see if it's possible, if so, I will be sending it to doug
John

Douglas.Sherida · #11 04-11-2007, 02:30 PM

Quote:

Originally Posted by dmorrison

Afraid your out of luck.
To my knowledge the receiving assembly, which is what your talking about is a part of the radiator that is attached while the bottom plastic and aluminum sections are apart. Every radiator I have ever installed. Those parts come already installed in the radiator. Either glued to the plastic or attached from the inside. The hose has the attaching "nut" and the segment on the radiator is for tightening only.
If you can attach another unit please post it so others will know. But again I thought the unit was installed at the factory and not a serviceable part.

Dave

You're probably right, it probably won't work. But, I've got very little to lose by trying.

I spoke with a very knowledgable mechanic from this forum regarding the problem and he gave me odds of fixing it at slim to none. He said that there is an o-ring on the inside of the fitting (inside the radiator body) and that it is very unlikely that I'll be able to get a seal. But, I've got very little to lose by trying.

My plan, if I can get the nut by Friday, is do a "dry run" by putting on the nut, adding water to the system and see if it leaks. If it holds for a couple hours, I'll disassemble, squeeze a little JB weld around the fitting, reinstall the nut and let it sit overnight. Next morning, fill her up with water, and go for a test drive. I'll probably be on the phone ordering a new radiator shortly thereafter, but I've got very little to lose by trying.

The only reason I think that it might work is that if I pull on the fitting (in the way that a nut would), it seems to seal up.

As they say, a picture is worth a thousand words... so, here is one that illustrates exactly the nut I am trying to describe.

5cylnoplugs · #12 04-11-2007, 03:27 PM

Do you really want to rely on a jury rigged repair at such a critical place? What are the consequences of the repair failing. I say new radiator, and sleep well at night.

Douglas.Sherida · #13 04-11-2007, 04:38 PM

Quote:

Originally Posted by 5cylnoplugs

Do you really want to rely on a jury rigged repair at such a critical place? What are the consequences of the repair failing. I say new radiator, and sleep well at night.

Believe me I understand what you are saying, but the seal held without a nut at all for over 4 years and 30 K miles (as long as I've had the car) and I'm guessing it may have been much longer.

The consequences of it failing are that the engine temp guage rises above its normal ~90 C operating temp and I pull over. Then I am back to exactly where I am already (minus a few bucks and about 10 minutes labor), except that I know that it can't be patched.

On the other hand, what do I gain if it works? 200-300 bucks for starters, an hour or two of labor, and the smug satisfaction of having MacGuyvered my way through yet another repair.

I don't commute daily in the car anyway, its a weekend thing (mostly to haul my kayak around for fishing). Unfortunately, my wife is going away for a few days next week, so I'll need the car to do anything other than get to work. I've always got AAA in a pinch, but I've never used it. Somewhat remarkable, considering my penchant for driving 20-50 year old cars.

The real problem (aside from my extreme frugality) is that the car is deteriorating quickly from rust. It kills me to see how fast the rust has spread in the last two years, especially considering that the car has less than 175 K miles on it. I don't need the "lifetime" repair since its unlikely I'll get more than 2-3 years before the rust kills it anyway.

going_postal · #14 04-11-2007, 06:22 PM

Try a radiator repair shop to see if they might have a junk rad. setting around or just the nut!!!
It will not hurt to ask!!

vstech · #15 04-11-2007, 07:00 PM

Bad news... mine is oem, and there is no nut... it is all one piece. sorry.
I can give you the Ph# of a rad shop here that has modine replacement radiators for 159.00 if you want it.
John