Hello,

Had a slow drip of transmission fluid at the radiator, where lower (of the two) transmission lines connects.

Couldn't get a replacement fitting or o-ring and the radiator was really old and worn out, so I replaced it. All new coolant hoses too.

So now the car starts and runs but I have the same leak. It's actually quite a bit worse.

There is a 'nut" that screws into the radiator (part of the radiator) and it has an o-ring inside of it. The new radiator is exactly the same (with a new o-ring). New radiator is a Nissans.

So I'm assuming the radiator isn't the problem since it's brand new, and both the old an new ones leak.

The hose is the 'quick connect' type with a clip. The hose ends in a tube with a flare near the end of it. It pushes into the radiator and clicks.

I've tried pushing harder, but it has already clicked. Tried putting a small o-ring on the end of the hose just before the flare, and that doesn't help.

I don't want to have to replace the hose because it looks in great condition, and also there are none in the USA or Canada and it will take 7-10 business days to get one from Germany.

These are not exact pics, but this is what the connector looks like.

This thing is screwed into the radiator (came with it) and has an o-ring inside it. You can see the clip on the outside too (works just like the coolant hoses do). This part is brand new on my car as it came with the radiator
https://www.google.ca/imgres?imgurl=...=1399&bih=8733

This is what the hose looks like that pushes into the above part. The o-ring in the radiator seals against the outside of this hose (supposedly)
https://www.google.ca/imgres?imgurl=...w=1399&bih=873

My next idea is to load the thing up with RTV, then let it dry completely (12 hours?) before starting the car. Not sure where to put the RTV as I don't want it inside the new radiator, but I'm thinking of coating the outside of the hose (from the tip, up to the flare) thickly with RTV and pushing the whole fitting together. Whatever oozes out is fine.

If I grab the hose and wiggle it, it's definitely loose but it seems like it should be that way. The top one is loose too (maybe not as much, but definitely loose) and only the bottom leaks because it's probably the one under pressure.

Car has been in garage 3+ weeks because of radiator (first one I got was bad, second one is fine) and now this... If I can stop this leak I just need to verify coolant level and I can drive! Until then I'm dead in the water......

Thanks!

 

What was wrong with the first replacement radiator? I would suspect an aftermarket rad could possibly have a poorly manufactured connection and if you forced the pipe in there and deformed it, then it will leak again on the new one. There is also the possibility of improper thread locker on the fitting causing it to leak through the threads. From what it sounds like though you have a worn pipe end. It should not be able to wiggle at all, maybe just a little bit but not much. Also make 100% sure that you are seating the pipe into the rad before clipping it. This will also cause deformation and leaks.

 

The metal pipe end is deformed. It takes very little. Replace hose.

 

The first aftermarket rad was a no-name and had shipping damage that I didn't notice till installed. When I filled it, it leaked. Removed it, and there was a crack in the plastic tank that let all of the water leak out.

The Nissans looks to be exactly the same quality as the original. Much better than the no-name too.

Didn't deform the pipe.. remember that it leaked on the original radiator, so that is why I am leaning towards the radiator not being the problem. There are no leaks where the fitting threads into the radiator, it's definitely at the "quick connect" part where the pipe plugs into the o-ring and clip.

The clip actually goes on first, so you push the pipe in and it clicks. The pipe does click in properly but still leaks.

So given the above (and what ALX posted) and considering that this thing has leaked since before I touched it, there are only two parts to replace.. the radiator and the pipe. So I have ordered a pipe and will install it in 2 weeks when it arrives (coming from Germany)

I find it interesting that NO dealer in Canada or the US has this pipe. I guess these things are so well built that they don't feel the need to stock them! Even a paying customer at MB who is spending $$$$$ for this repair would have their car on a hoist for 2 weeks waiting for the hose. Interesting.

Anyhow, will report back once the cooler hose is replaced and we'll see if that fixes it. If not, I'm heading towards RTV and eventually JB Weld

 

Quick update


alx mentioned the pipe may be deformed, so I have decided to order a new pipe. Backordered from Germany (no dealers have one in stock, and their distribution centre says they have none). 7-10 business days till I get it.


In the meantime, the car is on ramps with suspension collapsed as it hasn't been driven in 4 weeks.


Radiator is full and no leaks, all is good, just the transmission leak when I start the car. Will have to figure out how to get this cooler line out of the car. The 2 cooler lines are on opposite sides of the transmission but as they move to the front of the car, they get 'woven' together. Don't want to disconnect the 2nd line if possible! (and end up with the same leak...)


Will report back once I have the cooler line changed. Between a new radiator (which has a new o-ring installed) and new cooler line, I don't know what to replace next if this doesn't work!


If it still leaks I'm taking it to a mechanic I know, and will probably hand him my tube of JB Weld at the same time

 

Not sure if it's the same as the W221, but my 2007 GL450 (X164) has the "Jiffy-tite"® fittings in the radiator which I think the OP is referring to.
I purchased the internal O-Rings M-B # 0199975845 but with the radiator still in the vehicle, I was having a tough time trying to install the bottom one O-Ring. I was considering removing the radiator to get better access to them, but that's quite a project on the GL (which I did some years ago), so I did some hunting on the Internet and found that they're called Jiffy Tite fittings and found that Dorman has available the “Auto Trans Oil Cooler Line Fitting” as part number 800-619 and it looked identical to what was in my GL radiator. So I put a 19mm socket on it and it easily unscrewed from the radiator. With it removed, it was easy to see the larger O-Ring on the rear that seals against the internal oil cooler, and quite possibly the radiator housing also.

Not having the "Jiffy-tite" tool, I had removed the E clips to remove the cooler lines, so I put each clip in a vise and squeezed the ends together to restore the clip to a tighter diameter, and popped them back onto the fittings. Having the fitting out made it very easy to clean it and replace the internal O-Ring part Mercedes # 0199975845. I have not yet found a torque spec for it, but I have reinstalled it with about 24 Nm. I cleaned the cooler line and lining the pipe perpendicular to the radiator, and pushed the line in until the E clips snapped behind the pipe flare. In my photo, you can actually see the E clip tabs locking the pipe into place.

https://www.autozone.com/drivetrain/...3_772400_13424

Transmission Cooler Disconnect Tools:


Another video showing using the special tool, or a small screwdriver or pick.

 

Hello, I am in same boat with 2014 GL450. Lower tran cooler line leak from quick connect fitting and yes it's loose and move in and out more than quick connect other 2 line in same type fitting on rad). First thought is to replace radiator as fitting may have worn oring the inside the nut thing. What end up working out for you? I cleaned up the area other day to pinpoint leak better and made it worse from drop to way more than few drops.
Jamal

 

90% or more of the time replacing the O-rings and being sure the clip holds it tight is the end of the leak.

That said.... look at the size of the clips and materials used.... this ish is fragile on a good day. Be gentle with it.

Cleanliness is next to Godliness! Use a can of spray to get dirt from around the quick connect before disassembly.

As OP spoke of using RTV seal in a tube I want to be sure it is posted here....

DO NOT EVER use RTV in an effort to ‘solve’ a leak such as this. Any of that ish getting into fluid via a cooler line is now RTV delivered to the transmission pan where we pray the filter catches all of it as any of that ish getting past the filter is a transmission that IS coming apart. That and RTV applied as a glob on the outside of a fitting will not stop any pressure fed leak while guaranteeing misery in the future when it doesn’t work.
Yes; we can make life more miserable for ourselves. Don’t be that guy.

 

Thanks. Right on time. While I have radiator on order and on way I was leaning toward the oring replacement and clip check. I cleaned the area with degreaser to pinpoint leak and it leaked more when i started the car. Day later I started the car to further check, engine at operating temp and so does transmission and zero leak. I live in Minnesota and I belive cold play a role.i am going to replace the oring which I belive it can be done while rad in place.