Author Topic: Oil Leak from top of Oil Filter Cannister  (Read 518 times)

Jordan

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Oil Leak from top of Oil Filter Cannister
« on: October 22, 2024, 19:29:56 »
I recently did an oil change which included dropping the oil pan so I could replace the gasket.  To fix a leak from my power steering pump I then removed the pump and the bracket to replace the seals.  I also replaced the high pressure power steering fluid hose that runs from the steering gear to the pump.  I then started the car to fill the power steering reservoir (steering wheel back and forth) which is when I noticed oil leaking from the very top of the cannister containing the oil filter (see pic).  I know it coming from there because I cleaned everything up and took it for a short drive.  It looks like it is coming from the central screw, which I believe is the oil pressure sensor(?).  I'm wondering if maybe I hit it when I was tightening the power steering hose to the steering gear housing because they are close.  I put a wrench to the sensor but it appears tight.  The oil pressure gauge is pegged when I am driving which was normal so it's reading a pressure. It all looks wet in the pic because I sprayed the area with penetrating fluid.

I'm wondering why this location would just start to leak and if its a consequence of either the oil change/oil pan gasket change or the power steering pump removal.  If there was an oil pressure build up in the cannister I would expect it would leak either at the bottom bolt or at the o-ring at the top of the cannister.

I would appreciate any insight anyone might have.  I'm thinking of removing the sensor, cleaning it up, putting on some thread sealer and seeing if that stops the leak.  Thoughts?

Marcus
66 230SL  Euro 4 speed

ctaylor738

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Re: Oil Leak from top of Oil Filter Cannister
« Reply #1 on: October 22, 2024, 23:29:08 »
"I'm thinking of removing the sensor, cleaning it up, putting on some thread sealer and seeing if that stops the leak."

That's exactly what I would do as a first and hopefully only step.

Cheers,

CT
Chuck Taylor
1963 230SL #00133
1970 280SL #13027 (restored and sold)
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ja17

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Re: Oil Leak from top of Oil Filter Cannister
« Reply #2 on: October 23, 2024, 04:32:07 »
Marcus, it is not a sensor. It is a fitting and the oil gauge is mechanical and has an oil line going to it to measure the pressure. The fitting has a dual purpose. It provides the hook up for the oil line going to the oil gauge. In addition it is the receiver for the oil filter bolt from the bottom side. Most likely you loosened the fitting from below during the oil change. The solution is to loosen the oil filter bolt then tighten down the fitting. Next retighten the oil filter bolt.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
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Jordan

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Re: Oil Leak from top of Oil Filter Cannister
« Reply #3 on: October 23, 2024, 11:01:26 »
Marcus, it is not a sensor. It is a fitting and the oil gauge is mechanical and has an oil line going to it to measure the pressure. The fitting has a dual purpose. It provides the hook up for the oil line going to the oil gauge. In addition it is the receiver for the oil filter bolt from the bottom side. Most likely you loosened the fitting from below during the oil change. The solution is to loosen the oil filter bolt then tighten down the fitting. Next retighten the oil filter bolt.

Joe, that's great info.  I had no idea.  Thanks, I will do as you describe.
Marcus
66 230SL  Euro 4 speed

Charles 230SL

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Re: Oil Leak from top of Oil Filter Cannister
« Reply #4 on: October 23, 2024, 13:56:02 »
Lot of good information here regarding that fitting: https://www.sl113.org/forums/index.php?topic=32815.msg238934#msg238934.

Jordan

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Re: Oil Leak from top of Oil Filter Cannister
« Reply #5 on: October 23, 2024, 18:10:45 »
Just to follow up, Joe's remedy did the trick.  I loosened the bottom bolt and found I could turn the upper one with my fingers.  It was not tight.  Tightened it up and then tightened the bottom bolt and no more oil leak.  Thanks again Joe.
Marcus
66 230SL  Euro 4 speed