M-Class (W164) Produced 2006-2011: ML280CDI, ML320CDI, ML420CDI, ML350, ML500, ML550

Engine Oil leaking above the AC compressor drips onto power steering hose.

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Old Sep 7, 2021 | 12:57 PM
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2006 ML500
Engine Oil leaking above the AC compressor drips onto power steering hose.

Good day gents . I’m driving the wife car a 2006 ML500 with 144k
and it runs like a Swiss watch .
I do all the regular maintenance myself . Recently I replaced the PS pump and reservoir. And there was a lot of oil under the pump and I cleaned up everything pretty well . After that I replaced the power steering pressure regulator valve . This time with a genuine MB part. And now the oil I’m seeing is engine oil running down the top of the AC compressor and getting onto the hoses before it drips to the ground.
The PS pump and oil cooler look dry. Is there any way oil could be leaking from the PS bolts ? Or the cover that the pump attaches to?
Thank you
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Old Sep 13, 2021 | 04:02 AM
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2010 ML550 VIN WDC1641722A564750, 2010 B180
Look at the Oil Cooler above and next to the power steering pump. They have an upper and lowe seal. The upper one leak after a while. If you take the underbelly tray off and look up with a torch, if its leaking, you will see it on the bottom of the cooler. Check your coolant as well. If you have any oil or dark matter in the coolant, then its probably the seal noted. The cooler has coolant running through it that can mix with the oil, if the seal is worn. Check this youtube link. You can buy the seal on line and its a straightforward fix.
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