ATF leak, things to check and replace?
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
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2001 ML320
ATF leak, things to check and replace?
Hi all, I've noticed ATF leaking from my trans. oil pan. A mechanic told me it may be from where the electrical connector plugs into the conductor plate, but we haven't wiped the pan down to make sure. What he said makes sense though, and I hear it's a common thing with the 722.6 trannys. My pan is also slightly rusted, and the car is at 104,000 miles and hasn't had a trans. flush or fluid change yet. I want to change the pan, and want to fix the leak, so while I have the pan off, should I go ahead and replace the conductor plate from off the valve body? Again, while I have the pan off, should I replace the filter/strainer and magnet (if there is one which I think there is)? I've heard that as it leaks, it also creeps up the wire towards the trans. control module. Should I check this too as a precaution? Also, should I flush the trans. or just refill it? By flush I mean filling it, running it, then draining it a few times with new fluid to dilute out any remaining gunk. Ideas?
BTW, my car has been shifting a little harsh between 2nd and 1st and kinda seems to hesitate lately. Maybe due to fluid loss from the leak or bad connection somewhere? Could just be the cars age too.
BTW, my car has been shifting a little harsh between 2nd and 1st and kinda seems to hesitate lately. Maybe due to fluid loss from the leak or bad connection somewhere? Could just be the cars age too.
Super Member
Joined: May 2013
Posts: 504
Likes: 7
From: Harare, Zimbabwe
2003 ML55,2007 ML63
Do a flush the correct way as per the PDF. Change the conductor plate + pilot bushing + tranny filter+ tranny pan seal. You can check the ETC module. Remove it, open it & wipe all traces of oil. You will need a tranny dipstick.
Senior Member
Joined: Mar 2002
Posts: 282
Likes: 5
From: Brisbane, Australia
2002 ML320, 2003 A160
You don't need to replace the conductor plate if there's nothing wrong with it, or the pan. Rust can be removed and the pan cleaned and painted to prevent recurrence.
There are plenty of parts under your car that will be more than slightly rusted. Are you going to start replacing those too?
As for flushing vs drain and refill a few times, depends what kind of person you are. Do you think doing a job half-properly twice is as good as doing it properly once?
There are plenty of parts under your car that will be more than slightly rusted. Are you going to start replacing those too?
As for flushing vs drain and refill a few times, depends what kind of person you are. Do you think doing a job half-properly twice is as good as doing it properly once?
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
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2001 ML320
Thank you so much for the comprehensive instructions, they look awesome! Just one quick question, exactly what transmission is on my car? The PDFs referred to a few different 722.6 trannsmissions. For quick reference I have a 2001 ML320.
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
Likes: 0
2001 ML320
You don't need to replace the conductor plate if there's nothing wrong with it, or the pan. Rust can be removed and the pan cleaned and painted to prevent recurrence.
There are plenty of parts under your car that will be more than slightly rusted. Are you going to start replacing those too?
As for flushing vs drain and refill a few times, depends what kind of person you are. Do you think doing a job half-properly twice is as good as doing it properly once?
There are plenty of parts under your car that will be more than slightly rusted. Are you going to start replacing those too?
As for flushing vs drain and refill a few times, depends what kind of person you are. Do you think doing a job half-properly twice is as good as doing it properly once?
Senior Member
Joined: Mar 2002
Posts: 282
Likes: 5
From: Brisbane, Australia
2002 ML320, 2003 A160
Good decision.
The pan is made of thick steel and is never going to rust through.
If flushing, apart from the trans dipstick you will also need a 19 mm ring spanner.
You don't need a threaded hose fitting - use a plastic tube instead as described here: http://www.benzworld.org/forums/w163...l#post10340425
The pan is made of thick steel and is never going to rust through.
If flushing, apart from the trans dipstick you will also need a 19 mm ring spanner.
You don't need a threaded hose fitting - use a plastic tube instead as described here: http://www.benzworld.org/forums/w163...l#post10340425
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
Likes: 0
2001 ML320
Good decision.
The pan is made of thick steel and is never going to rust through.
If flushing, apart from the trans dipstick you will also need a 19 mm ring spanner.
You don't need a threaded hose fitting - use a plastic tube instead as described here: http://www.benzworld.org/forums/w163...l#post10340425
The pan is made of thick steel and is never going to rust through.
If flushing, apart from the trans dipstick you will also need a 19 mm ring spanner.
You don't need a threaded hose fitting - use a plastic tube instead as described here: http://www.benzworld.org/forums/w163...l#post10340425
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Senior Member
Joined: Mar 2002
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From: Brisbane, Australia
2002 ML320, 2003 A160
It comes in a 5 litre bottle, so buy 15 litres. If you read the instructions, it explains that you need 14 litres, so you have some spare for topping up.
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Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
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2001 ML320
If the Fuchs fluid is 4134, then it's on this list approved by MB, so it's good. --> https://bevo.mercedes-benz.com/bevol...236.14_en.html
It comes in a 5 litre bottle, so buy 15 litres. If you read the instructions, it explains that you need 14 litres, so you have some spare for topping up.
It comes in a 5 litre bottle, so buy 15 litres. If you read the instructions, it explains that you need 14 litres, so you have some spare for topping up.
Super Member
Joined: May 2013
Posts: 504
Likes: 7
From: Harare, Zimbabwe
2003 ML55,2007 ML63
Get the Fuchs 4134. That is the correct ATF for your tranny. Changing the conductor plate will be a prophylactic measure & will give you peace of mind for many years. As DrX said, you don't need to change the pan. You have a 722.6 tranny.
Finish the tranny issue, then we can attend to the transfer case. It uses different ATF.
Finish the tranny issue, then we can attend to the transfer case. It uses different ATF.
Senior Member
Joined: Mar 2002
Posts: 282
Likes: 5
From: Brisbane, Australia
2002 ML320, 2003 A160
If you want peace of mind, don't put leftover 4134 in the transfer case.
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
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2001 ML320
I've ran the idea (trans. flush) past a few mechanics, and they've all advised me not to even bother with this transmission service. They have even said that I run the risk of the tranny not working after the service. My father and a friend of mine (both mechanics) said that changing the older, thicker, dirtier fluid to new, clean, thinner fluid will not make the tranny run because the newer fluid will cause the clutch packs to slip. I'm not entirely sure what that means. I'm not familiar with the very specific inner workings of an auto tranny, so I'm not sure if what they are saying is truly valid. Nonetheless, I've respected their opinions due to them being far more experienced than me. What's your opinion? Seeing that you did the flush and assuming your ML is working perfectly fine. I'm not entirely sure if I want to go through with this considering all the bad things I've heard.
Super Member
Joined: May 2013
Posts: 504
Likes: 7
From: Harare, Zimbabwe
2003 ML55,2007 ML63
They don't know what they are talking about!!!! Nonsense!!!! Do the tranny service!!!
People neglect the tranny. After developing mechanical faults, they decide to service it(too late). And when the tranny fails(due to neglect) they blame the servicing. This is were these "granny's tales" come from.
People neglect the tranny. After developing mechanical faults, they decide to service it(too late). And when the tranny fails(due to neglect) they blame the servicing. This is were these "granny's tales" come from.
Senior Member
Joined: Mar 2002
Posts: 282
Likes: 5
From: Brisbane, Australia
2002 ML320, 2003 A160
They have even said that I run the risk of the tranny not working after the service. My father and a friend of mine (both mechanics) said that changing the older, thicker, dirtier fluid to new, clean, thinner fluid will not make the tranny run because the newer fluid will cause the clutch packs to slip.
My trans has done 13,000 miles and 13 months since I flushed it. It's working better than ever. Probably because I replaced all the black fluid that was full of carbon and cleaned the sludge and tiny metal fragments out of the pan (normal wear). I didn't change the conductor plate, according to the "if it ain't broke, don't replace it" philosophy.
You have a leak, so you have to drain it. Do you want to put the dirty old fluid back in the top?
I've been driving this ML every day for 11.5 years. Do you think I have more experience than them?
Last edited by DrX; Nov 4, 2015 at 06:47 AM.
Thread Starter
Junior Member
Joined: Sep 2014
Posts: 34
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2001 ML320
I read these stories and opinions before I flushed mine. I didn't believe any of them.
My trans has done 13,000 miles and 13 months since I flushed it. It's working better than ever. Probably because I replaced all the black fluid that was full of carbon and cleaned the sludge and tiny metal fragments out of the pan (normal wear). I didn't change the conductor plate, according to the "if it ain't broke, don't replace it" philosophy.
You have a leak, so you have to drain it. Do you want to put the dirty old fluid back in the top?
I've been driving this ML every day for 11.5 years. Do you think I have more experience than them?
My trans has done 13,000 miles and 13 months since I flushed it. It's working better than ever. Probably because I replaced all the black fluid that was full of carbon and cleaned the sludge and tiny metal fragments out of the pan (normal wear). I didn't change the conductor plate, according to the "if it ain't broke, don't replace it" philosophy.
You have a leak, so you have to drain it. Do you want to put the dirty old fluid back in the top?
I've been driving this ML every day for 11.5 years. Do you think I have more experience than them?
