Hey guys,

I was getting ol'Betsie out of winter storage, and discovered a pretty major transmission leak. I realized something was up when I took her on her last trip of the season last year, but now just confirmed I do indeed have a problem.

The bracket underneath the oil pan seems to have lost its rubber and wore a pinhole leak through the passenger side transmission line. It's not dripping out, it's streaming out when the engine is running. The drivers' side line is still OK; that bracket still has the rubber (though I will be replacing that rubber now!).

So question:

I know this is a fairly common problem on these cars. What kind of fixes have you guys performed for this, and can you recommend anything?

I would rather just replace the whole line to be honest, but I haven't been able to find that metal transmission line anywhere. Can that part no longer be had?

What are my options here? I really want to get ol'Betsie out on the asphalt now that the sun is shining and the snow is melting.

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

JB weld. It works. Just be sure to clean it really well first.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

I just cut at hole then used hose,did not need bracket anymore

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

So JBWeld might actually work? That is a repair some folks have done successfully?

I did find some people that cut out the old line and put in some hose and double clamp it, but I read that if you don't put the bracket back somehow, that whole line will then vibrate so much you're going to eventually spring a leak somewhere else. I'm not handy enough to fabricate a bracket I don't think, so my only concern with the hose would be how to securely attach it.

Anyone ever replaced the whole line? How much of a PITA was that? Line seems fairly accessible to me. Can't be any worse than an oil cooler line, can it?

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

It's been holding on my 124 for 4.5 years now...

Proper prep and curing is essential.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Very very nice! I'm glad it's been holding for you. I've done some research on the JBWeld, but I've come across a bunch of folks that had it crack soon after. I'm sure you're right and it's all in the good prep work, but it makes me a little reluctant to go this route.

I really can't find the line for sale anywhere, so I'm going to just cut the broken piece out with a pipe cutter and put a piece of flexible transmission hose that I'll double clamp. That should hold while I hunt for a new line, although I already kind of know this is going to be one of these temporary repair jobs that'll turn permanent...

I'll need to come up with some way to fasten it back to the oil pan though. The original bracket will not be possible because I don't want to clamp on just the rubber hose. Hmmm...

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

The "Temporary" repair with ATF rated Hose (Double Clamped) will outlast
your search for another solution.

BUT , If you wanna go "Whole Hog" AR:
You could Braise fittings for (Aircraft Quality) Stainless Steel Braid encased
Teflon inner liner hoses and replace ALL the ATF cooler lines.

__________________
'84 300SD sold
124.128

Some people have used these but it requires that you cut the tubing.

Attached Thumbnails

 

__________________
84 300D, 82 Volvo 244Gl Diesel

Yeah, the more I'm researching this, the more I realize that's the way to go. I'll need to go get a tube cutter and some parts, but I'm planning on getting this knocked out this weekend.

That looks really nice and fancy! I have no problems cutting the tube (I think), but I wouldn't know how to proceed and attach that part to it. I have no tools to thread or flare anything.

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

Make sure when using the tubing cutter to ream outbthe inside of the tube before installing the union. Alomuse caution when tightening the union nuts so as not to distort the tubing.

I believe that to be a compression fitting. Only simple wrenches required to tighten it. Illegal on brake lines but more than adequate on a transmission cooler line.

Had this exact issue recently. I did the rubber hose fix until I sourced the lines right here from Pelican. ~$100 each (ouch!). Some of the local parts houses had no clue on what type of rubber hose to use so I opted for fuel injector rated (60psi I think). Used the leftover rubber hose to make new rubber bits for the tie brackets.
123-270-33-96-MBZ
123-270-40-96-MBZ
Get a set of new crush washers for the fittings at the transmission if you go with the new lines.

__________________
1985 300D
The rest:
1957 MGA (comatose)
1965 Falcon (sleeping)
1966 E-100 (rust test in progress)
1976 Ford 3400 D Tractor (workhorse)
1978 Mercury Zephyer (5L playtoy)
1995 Isuzu NPR D (fetcher)
1998 Subaru Legacy (Spare)
2000 Toyota Sienna (School bus)
2008 Toyota Prius (Commuter)

cut the steel line and slip rubber fuel line hose over the two ends and clamp. i used about two feet of hose. i dont think theres a lot of pressure on this line, or none of these repairs would work very well.

Thanks so much for the part numbers! Very helpful.

I'll do the quick hose repair first so I get to drive Betsie a bit before the raining season starts (I try to keep her out of the rain as much as I can), and once the downpours start at the end of summer I have time to put a proper line in.

__________________
"The MB W123 is so bulletproof, you can drive them forever. Which is a good thing as it takes that long to get anywhere."
Betsie: 1984 W123 300D (hobby, 280k miles)
Myrla: 2001 Mazda Protege 2.0 ES 5spd (daily driver, 130k miles)
The Turd: 2007 Toyota Camry (wife's car, 118k miles)

You can try one of the other methods and if it does not work out for you you can try another.

You don't need to flare or tap anything.

Might want to look up some instructions on the internet to see if it is what you want to do.

There is 2 small brass collar, you slide the nut on and you slide a brass collar over the tube. When you thread on and tighten the Nut the collar compresses around the tubing and it seals.
You do the same to the other side.

Don't cut the tubing too short and if the tube is too rusty the collars won't seal around the tubing.

__________________
84 300D, 82 Volvo 244Gl Diesel