ATF leak on a 722.6 transmission - PeachParts Mercedes-Benz Forum

Boston Benz · #1 12-31-2011, 04:10 PM

RE: a 2001 E320, this is really strange - I've discovered a leak where the ATF pan gasket wraps over the ATF pan. The gasket wraps over and leaves about an eighth of an inch of metal pan exposed. Mine is leaking right at that 1/8 of an inch. I'll wipe that entire 1/8" clean and dry, and within ten-minutes ATF is oozing/weeping (it seems) from under the pan gasket... I don't get it. I changed the ATF 12,000 miles ago and there haven't been any leaks at all. The gasket was bought at the dealer, the torque specification was observed at 8Nm. Two-days ago, I tightened it to 10Nm, and it is still leaking. Usually a leak like this will come from where the gasket meets the transmission, this one seems to be from underneath where the pan meets the gasket. I'm losing a lot of ATF over the course of two-weeks, about two-quarts. What gives?

RichardM98 · #2 12-31-2011, 04:39 PM

I would suggest just replacing the gasket. If installed correctly, it shouldn't leak. If you decide to do so pay careful attention to the standoffs. They need to be in the correct position. If they are there's no need to increase the torque. Actually, it won't do any good since the standoffs determine the pressure on the gasket not the mounting bolt.

I hope you are adding the correct AFT (MB spec) to maintain the proper fluid level since these transmissions are very sensitive to low/high fluid level.

whunter · #3 12-31-2011, 05:03 PM

Quote:

Originally Posted by Boston Benz

RE: a 2001 E320, this is really strange - I've discovered a leak where the ATF pan gasket wraps over the ATF pan. The gasket wraps over and leaves about an eighth of an inch of metal pan exposed. Mine is leaking right at that 1/8 of an inch. I'll wipe that entire 1/8" clean and dry, and within ten-minutes ATF is oozing/weeping (it seems) from under the pan gasket... I don't get it. I changed the ATF 12,000 miles ago and there haven't been any leaks at all. The gasket was bought at the dealer, the torque specification was observed at 8Nm. Two-days ago, I tightened it to 10Nm, and it is still leaking. Usually a leak like this will come from where the gasket meets the transmission, this one seems to be from underneath where the pan meets the gasket. I'm losing a lot of ATF over the course of two-weeks, about two-quarts. What gives?

You need to look at this, it is a known leak issue = superseded four times by MB.

2035400253 Transmission Electrical Connection Spacer
2035400253 Transmission Electrical Connection Spacer

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Boston Benz · #4 12-31-2011, 09:25 PM

I just looked up at the front of the transmission on the passenger-side at the pan, and sure enough, ATF is oozing out of that connector. Wow, I never would have thought to look up that high on the transmission. It appeared to be seeping out of the gasket/pan area. Looks are deceiving... Yes I am using the proprietary MB ATF and I have the $65 dipstick too. Thanks.

RichardM98 · #5 12-31-2011, 09:58 PM

Glad you found the problem. Several DIY's online to do repair. Usually just replacing the O-rings solves the problem.

engatwork · #6 12-31-2011, 10:00 PM

It is a straight forward job to replace the leaking connector.

whunter · #7 12-31-2011, 11:55 PM

Quote:

Originally Posted by Boston Benz

I just looked up at the front of the transmission on the passenger-side at the pan, and sure enough, ATF is oozing out of that connector. Wow, I never would have thought to look up that high on the transmission. It appeared to be seeping out of the gasket/pan area. Looks are deceiving... Yes I am using the proprietary MB ATF and I have the $65 dipstick too. Thanks.

I am glad it is a simple inexpensive repair.

Have a happy new year

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