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I just had some recall work done on my 08 C350 at my local dealership and they went through and 'checked' some things and came back to me with a long list of things they want me to pay them to fix. [Strange because I just had a different recall job performed at a different (more reputable) dealership and they didn't mention any of this, but anyways].
One of the things they mentioned on their paperwork was 'Transmission cooler lines leaking heavily.' I'm trying to look up some information on this but can't find anything. Can someone here tell me 1) if this is something I need to be worried about 2) how I can check myself to see if it's leaking 3) how to fix it and 4) can I add oil back in to keep the level proper until I can fix it? I've done all the service myself up until now and am pretty good at fixing things if I have some guidance and I personally don't trust these guys so any help is appreciated.
Yes, losing tranny fluid is bad, especially since you don't know how much you are using when it is leaking.
I would put the car on ramps and remove the plastic covers that run along the bottom of the engine bay and look for any leaks. Tranny fluid is usually red (unless Mercedes has special fluid), so if you see any of that then you've hit the spot.
As far as fixing, it depends where the leak is. Is it a leak in one of the lines itself, at the junction where it connects to the tranny, etc? If it's just a leak in the lines you might be able to splice in rubber hose. Not everyone likes using rubber hose, but I ran it in my Corvette which ran high temperatures and never had an issue.
- If you look at figure four on this page you'll see a junction of the tranny cooler lines. This should give you an idea of what they look like...
I just had some recall work done on my 08 C350 at my local dealership and they went through and 'checked' some things and came back to me with a long list of things they want me to pay them to fix. [Strange because I just had a different recall job performed at a different (more reputable) dealership and they didn't mention any of this, but anyways].
One of the things they mentioned on their paperwork was 'Transmission cooler lines leaking heavily.' I'm trying to look up some information on this but can't find anything. Can someone here tell me 1) if this is something I need to be worried about 2) how I can check myself to see if it's leaking 3) how to fix it and 4) can I add oil back in to keep the level proper until I can fix it? I've done all the service myself up until now and am pretty good at fixing things if I have some guidance and I personally don't trust these guys so any help is appreciated.
I would likewise eyeball that "issue" before committing. I don't trust dealers. I have experienced and heard of too many horror stories.
There's not much to checking the cooler lines. Can you wrench at all? With the car up on stands all you have to do is remove the lower covers to see the entire length of cooler hose. You can also rent some lift time. All you need is an 8mm socket if memory serves.
I would likewise eyeball that "issue" before committing. I don't trust dealers. I have experienced and heard of too many horror stories.
There's not much to checking the cooler lines. Can you wrench at all? With the car up on stands all you have to do is remove the lower covers to see the entire length of cooler hose. You can also rent some lift time. All you need is an 8mm socket if memory serves.
Thanks y'all. I'm good with a wrench and have done all of them maintenance thus far on my own. The first thing the service guy asked me when he brought me the paperwork was where I get service done and I told him I do it and he got a little awkward/quiet.
Where exactly do the hoses stretch (what direction, from where to where)? I'm gonna jack the car up as soon as I can get into a garage and check it out.
Thanks y'all. I'm good with a wrench and have done all of them maintenance thus far on my own. The first thing the service guy asked me when he brought me the paperwork was where I get service done and I told him I do it and he got a little awkward/quiet.
Where exactly do the hoses stretch (what direction, from where to where)? I'm gonna jack the car up as soon as I can get into a garage and check it out.
See attached doc for the transmission cooler connections on a 2WD 722.9. Leaks up front should be evident, but any leak should be readily visible, along with stains on the protective covers you'll be removing.
My money is on a greedy service advisor. Good luck, and report back!
ATF loss is fix ASAP or sooner. If it is weaken hose, replace the hose. If the hose is sweating or bulging, it about to go. There are replaceable o-rings where the pipes mate to the tranny or just might need tightening for the moment. Easily replaced. Best to do the ATF change with TC drain, bolt changes, filter, gasket and o-ring all at once.
ATF has a distinct smell. If it get dirty in can look like oil. First ATF looks black from the friction material in the tranny. Looks more red after the first change.
Ok guys. I raised the car and took the covers off from the front of the vehicle. It seemed like the front left (passenger side) had some signs of fluids on the plastic covers so I looked there and it seems like one of these lines might be leaking a small amount of oil. The oil seems clearish brownish, looks like fresh engine oil. Check out the pics below:
This seems to be a culprit. It looks like it's has some oil on it and there was some buildup on the plastic underside that seems to have been blown back from highway driving.
Upclose. Is this a cooler line? I can't tell but the green area seems to be the area with the issue. This tube seems a little loose (i can move it around and twist it) - can it be tightened? If so, how? How does this tube attach properly to whatever it's connected to? I don't want to move it one way or another and potentially risk making it worse.
This is where that line (along with the second one behind it, which looks clean and dry) connects. Looks a little dirty but doesn't seem to be leaking anything????
Can anyone explain how those lines are tightened? I'm afraid to touch it and don't want to make it worse but am not sure how the line actually attaches.
Can anyone explain how those lines are tightened? I'm afraid to touch it and don't want to make it worse but am not sure how the line actually attaches.
Looks suspiciously like the ones on Bimmers except without the release ring.
Are those quick connectors repairable, i.e., has replaceable o-rings. If they are leaking, is it disconnect, clean and reconnect without changing any parts?
BTW: on the 2009 e320, the AFT cooler does not appear to be connect to the radiator. The cooler lines from the external cooler goes directly to the transmission. So not antifreeze contamination possible?
Last edited by dave2001auto; May 15, 2016 at 12:43 PM.
Are those quick connectors repairable, i.e., has replaceable o-rings. If they are leaking, is it disconnect, clean and reconnect without changing any parts?
I'm sure you could if you really tried, but the o-ring is usually too deep into the assembly making removing it impractical. The plastic bits will also be brittle after a few years of service.
Side note, I wouldn't be surprised if the leak is cause by rolling the o-ring when it was assembled at the factory, i.e. not enough assembly lube.
I'm sure you could if you really tried, but the o-ring is usually too deep into the assembly making removing it impractical. The plastic bits will also be brittle after a few years of service.
Side note, I wouldn't be surprised if the leak is cause by rolling the o-ring when it was assembled at the factory, i.e. not enough assembly lube.
Does this line tighten into place or does it snap or something? Can I pullback the black plastic part on the end or is that piece not removable? I don't really get how it connects and why it has edges that want to accommodate a wrench. I guess what I'm tying to say is I'm hoping I can just tighten it and be done, lol.
Does this line tighten into place or does it snap or something? Can I pullback the black plastic part on the end or is that piece not removable? I don't really get how it connects and why it has edges that want to accommodate a wrench. I guess what I'm tying to say is I'm hoping I can just tighten it and be done, lol.
Probably something like this -
With the tool inserted, the hex is so you can twist the hose side to side to break any o-ring stiction.
Is one end of the tranny line metal and the other hose? It's hard to tell in the picture.
If it gets to the point where you are thinking of taking it to the dealer, you could always cut the lines and splice hose in. Knowing how much Merc dealers like to charge ridiculous amounts of money for small things, I'd do that in a heartbeat over having them fix it.
Is one end of the tranny line metal and the other hose? It's hard to tell in the picture.
not entirely sure what you're wondering but I can only see the two hoses that are in the images (cooler side), not sure about what is on the opposite side.
It doesn't seem to be leaking very much (very minimal actually) but the leak is definitely coming from where I marked on the image I took. Can someone confirm how the line is installed? Is it held in place by those C clips (like the below image) and just pressed in or is it tightened ? I'm scared to start yanking on it out of fear or making it worse.
If I were to just take the hose apart and disconnect it right where the leak is, would oil come pouring out? The actual rubber hose seems fine - the problem is the joint where it connnects.
I also wonder if the metal end is flared. Usually if someone is installing an aftermarket tranny cooler the kit will have some sort of flared line to splice into the existing hose.
From the CVX's diagram, it looks as the plastic has two exterior parts. You can try if pushing in on the plastic ring that is next to the metal pipe will release the internal retainer and allow the metal to come out. I am not certain but that how some of the gas fitting are done at work. Push the pipe and hose fittings together while pushing the plastic ring on the metal pipe side towards the hose, then without releasing the pressure on the plastic ring, pull the hose connector from the metal pipe. Of course, don't pull on the rubber but use the pull on the metal hose connector.
You will need to clear up the area before disconnecting the hose from the pipe, so dirt will not enter the fluid lines. I would also thoroughly clean the connectors before refilling.
Been watching a lot of DIY youtube videos about similar repairs and all of them seem to use one of two methods. I'm thinking I'm just going to disconnect the line (pretty sure that black plastic cover pulls back and reveals a clip that holds the rubber hose end in) and pull the two apart, cut off the metal that's attached to the rubber hose (where it's leaking) and then connect the two using a fuel line and hose clamps (with some flaring on the hard tubing side if it's not already).
The only thing I'm worried about is disconnecting the line and losing oil..I'm hoping only minimal stuff drips out? I've also been reading a lot about compression fittings (on the hard tube end) but it seems like cutting+flaring+sliding a rubber hose over it with hose clamps would be a lot more secure...
Unless anyone knows if the internal o-rings are replaceable?
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