Transmission Fluid Leak: Connector?

213323 Views 155 Replies 61 Participants Last post by khomer2, Jun 17, 2020

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Discussion Starter · Mar 21, 2008 (Edited)

ladboy said:
Also noticed a few drops of oil under the car. Its about the center between the two front seats. The liquid is definately not engine oil - it seems oily though. Checked the brake oil - level is fine. I'll try to get a photo from under the car when I jack up the car for the brakes. Thanks everyone - One project complete ;-).

Hey, lad. Good job, glad you got a big one out of the way.

The leak (given your described location) sounds as though it could be AT fluid. There is a connector that is a known potential issue on the 722 transmission, often it leaks so badly that the fluid runs up the harness into the TCM and ruins it. That's the FIRST place to check.

Take care and enjoy the SMOOTH ride,
Greg

Edited to add Star Bulletin for this known issue.

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ladboy

· #2 · Mar 26, 2008

Took a photo. Does it look like the AT Pan gasket may be faulty ? AT Fluid change may be in order. What do you think ? Where is the sensor that everyone talks about from where it leaks ?

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Discussion Starter · #3 · Mar 26, 2008

Hey, ladboy.

Since this issue is not on point for the other thread I made a new one for you, plus this will get it some exposure it would have otherwise missed.

That's certainly a significant leak, probably is the connector but the guys who have suffered through that will chime in to confirm or "disconfirm", as it were. (Bonus points if you recognize the movie line.)

Take care and enjoy the ride,
Greg

JOE55

· #4 · Mar 26, 2008

yeah it looks like the pan gasket needs to be replace.

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tirona

· #5 · Mar 26, 2008

it would be smart for all w210 owners, especially the ones with the earlier years to check the connector that greg is talking about. the part costs like $10 and is super easy to change. when i checked my car it was a little wet, it wasn't bad where the atf went to the tcm, but i'm really glad i caught it early.

ladboy

· #6 · Mar 26, 2008

Connector Location

Where is the connector that everyone is talking about ? I would appreciate if someone can post a photo of the location. Thanks.

tirona

· #7 · Mar 26, 2008

if i remember it right is connected to the left wire (passenger side) from the above pic, and you don't need to take the pan off. follow the wire to the pan and i think a little rectangular piece clips off, and take it out. it was a while back so i could be a little off, and also mine is a 1997, and could be a little different from the newer ones since it was the first 722.6 version.

Franasia

· #8 · Mar 27, 2008 (Edited by Moderator)

A few pictures

I have quickly put together some of the pictures I took when replacing mine last summer. Please do not take it as a tutorial but rather as a simple illustrative guide. This is a relatively simple job.

If no access to a lift, raise the front on ramps. First step is to remove the side stainless steel shield shown hanging on some the pictures. The electric plug is a two part component. The ivory color piece is a twist off mechanism, rotate it probably 3/4 of a turn or so and remove the electric plug, which will stay hanging from its wire harness. Installation is the reverse.

The red O ring needs to be purchased separately. The last picture shows the piece you have to purchase that does come with its O rings.

I apologize for any omissions and hope it helps.

Cheers

Reactions: 1

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Discussion Starter · #9 · Mar 27, 2008 (Edited)

Franasia said:
I have quickly put together some of the pictures I took when replacing mine last summer. Please do not take it as a tutorial but rather as a simple illustrative guide. This is a relatively simple job.
...
I apologize for any omissions and hope it helps.

Cheers

Hey, Franasia.

Thank you for taking the time to put this together, quickly or not. Do you still happen to have the part numbers from your invoice, etc? If so please PM them or post and I'll add them in. I think this is really useful, and a great example of the forum working for everyone.

Denials, disclaimers and apologies aside, I thought this was worthy of inclusion in the DIY thread, and exercising my mini-mod prerogative, it is.

Take care and enjoy the ride,
Greg

tirona

· #10 · Mar 27, 2008 (Edited)

Franasia said:
The red O ring needs to be purchased separately. The last picture shows the piece you have to purchase that does come with its O rings.

Cheers

franasia, very nice write up. so you replaced the red o-ring also along with the last piece? when i replaced mine i didn't change the red o-ring, only the connector part that twists off (the last picture from franasia's pdf). next time i change the tranny fluid i will for sure.
was your connector wet with atf? in my case when i twisted the connector off, the part that doesn;t twist off was a little wet (picture 1 from franasia;s pdf). i cleaned it with some electronics cleaner and let it dry/drip for a little bit until i was sure it was dry, then i twisted on the new connector part (last picture from franasia's pdf) and put everything together. and i didn't lose a lot of atf, so didn't need to add more.
by the way the pic shows the location of the connector from the above pic, even though franasia's pictures make it pretty clear where it is.

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E430SportMB

· #11 · Mar 27, 2008

Hello,
Forgive me , but I am lost here . May I know what does the connector do for the tranny, and what is it called? Does it monitor the system? . . . . . Sorry for the idiotness , thanks.

ladboy

· #12 · Mar 27, 2008

AT Plug Adapter

Franasia/tirona - Thanks for putting the great pictorial & for point it out in my photo. It looks bigger than I thought. I found out that the 'device' is called AT Plug Adapter - (part number - J2050-277685 at mercedesshop dot com). Costs just $7.18. Planning to DIY this and here is the list that I think I need.
1. AT Cover Pin (plastic part that is one time use)
2. AT Drain Plug Seal (Washer)
3. AT Filter
4. AT Pan Gasket
5. AT Plug Adapter (device that we are talking about)
6. AT Drain Plug
7. AT Fluid (MB)

Does the 2001 model come with a magnet ? Am I missing anything here ? I will take photos when I do this.

Franasia

· #13 · Mar 28, 2008

gregs210 said:
Hey, Franasia.

Thank you for taking the time to put this together, quickly or not. Do you still happen to have the part numbers from your invoice, etc? If so please PM them or post and I'll add them in. I think this is really useful, and a great example of the forum working for everyone.

Denials, disclaimers and apologies aside, I thought this was worthy of inclusion in the DIY thread, and exercising my mini-mod prerogative, it is.

Take care and enjoy the ride,
Greg

Part No. 203 540 02 53. Cost $7.70.

Franasia

· #14 · Mar 28, 2008

tirona said:
franasia, very nice write up. so you replaced the red o-ring also along with the last piece? when i replaced mine i didn't change the red o-ring, only the connector part that twists off (the last picture from franasia's pdf). next time i change the tranny fluid i will for sure.
was your connector wet with atf? in my case when i twisted the connector off, the part that doesn;t twist off was a little wet (picture 1 from franasia;s pdf). i cleaned it with some electronics cleaner and let it dry/drip for a little bit until i was sure it was dry, then i twisted on the new connector part (last picture from franasia's pdf) and put everything together. and i didn't lose a lot of atf, so didn't need to add more.
by the way the pic shows the location of the connector from the above pic, even though franasia's pictures make it pretty clear where it is.

tirona, I did not replace the red o-ring since I was made to believe by the parts person everything was included with the part but it was not. I wasn't familiar with the part at all at the time. I was in the middle of doing it when I found out it didn't come with it so I had no choice than using the old one. It has not leaked at all ever since.

The connector was indeed wet and all the wiring going up to the control unit as well. I just dried it up with paper towels.

Cheers

Franasia

· #15 · Mar 28, 2008

3

E430SportMB said:
Hello,
Forgive me , but I am lost here . May I know what does the connector do for the tranny, and what is it called? Does it monitor the system? . . . . . Sorry for the idiotness , thanks.

It hooks up the EGS (a.k.a. TCM or TCU), Transmission Control Module, to the transmission. On some earlier units the EGS gets flooded with ATF. Mine, which is the newer version, is a completely sealed unit. I attached some pictures I took when replacing the electric plug. The lower picture shows the EGS location in the engine compartment with it removed.

Hope it helps.

Cheers

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E430SportMB

· #16 · Apr 4, 2008

Thanks for the input. Sorry for the delay in response. Sure helps in my next DIY.

om87

· #17 · Apr 30, 2008

Franasia said:
It hooks up the EGS (a.k.a. TCM or TCU), Transmission Control Module, to the transmission. On some earlier units the EGS gets flooded with ATF. Mine, which is the newer version, is a completely sealed unit. I attached some pictures I took when replacing the electric plug. The lower picture shows the EGS location in the engine compartment with it removed.

Hope it helps.

Cheers

I have a 97 E320 with 60K miles it refuses tp shift out of first gear I have reverse and first gear my independent mechanic say he checked trouble codes and received " lost connection code" with the conducter board inside the transmission located above the valve body. Does this make any sense? Would a leaking connector cause the same symptoms ? Would appreciate any and all feedback.

tirona

· #18 · Apr 30, 2008

om87 said:
I have a 97 E320 with 60K miles it refuses tp shift out of first gear I have reverse and first gear my independent mechanic say he checked trouble codes and received " lost connection code" with the conducter board inside the transmission located above the valve body. Does this make any sense? Would a leaking connector cause the same symptoms ? Would appreciate any and all feedback.

maybe it would if the fluid traveled too far. did your mechanic check the connector for leakage? did he check with the mb tranny dipstick the fluid level? hopefully is nothing serious.

om87

· #19 · Apr 30, 2008

tirona said:
maybe it would if the fluid traveled too far. did your mechanic check the connector for leakage? did he check with the mb tranny dipstick the fluid level? hopefully is nothing serious.

Mechanic to do fluid change and filter and connector, he is to drop valve body and check connector plate.Hopefully he wil find the problem. Thanks for your responce will let you know his findings. om87

Raylee177

· #20 · Apr 30, 2008

I had mine replaced 2 years ago with same issue. It was very nice of you to show picture so others could benefit from your experience.

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