Author Topic: oil cooler replacement  (Read 2599 times)

Kenneth Gear

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oil cooler replacement
« on: January 14, 2005, 19:39:24 »
Has anyone replaced their oil cooler whoch is bolted to the side of the raditor?  How big a job is it to replace?  Is it a do-able for a do it yourselfer?  Is it relatively straight forward or is it better left to a pro?

Ken G
1971 280 SL
Silver/red
Ken G
1971 280 SL Silver/red

ja17

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Re: oil cooler replacement
« Reply #1 on: January 14, 2005, 20:53:56 »
Hello Ken,
Make sure you have the correct size wrenches for the oil lines first (22mm, 27mm). Always use two wrenches to unfasten or you may damage the radiator (one to hold radiator fitting and one to unfasten oil line). The inside fitting may require a "skinnier" wrench than usual.


Removal of the battery is beneficial and safer during the job. The radiator with the oil cooler is normally removed together which involves removing the hood in most cases.  Read the posts on hood removal first if you choose that route.
Some owners prefere to remove the radiator from below without disturbing the hood.
Two "carriage" like bolts hold the oil cooler to the radiator side. The nut is a 10mm.

These oil coolers are made of steel to withstand high oil pressures and prone to corrosion in salty regions and northern winters. Leakage and loss of oil can result from failure by corrosion. Normally these CANNOT be repaired by a radiator shop. They are fairly expensive to replace with new. Here again I believe many sedans of the era with these M130 engines used the same oil cooler.

During restoration these should be carefully bead blasted and re-painted to protect the steel fins and cores from corrosion.

The expensive high pressure rubber oil lines are also usually ready for replacement after twenty or thirty years also. At least check them carefully. The fittings on the ends are removable and the hoses can be rebuilt, but consider the risks involved in this.

If you have an automatic transmission replace the transmission rubber hoses going into the radiator at this time also. These are fairly inexpensive and easy to change.

Good Luck!




Joe Alexander
Blacklick, Ohio
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
1965 220SE Finback

Kenneth Gear

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Re: oil cooler replacement
« Reply #2 on: January 15, 2005, 12:42:36 »
Thanks for that comprehensive answer..much appreicated!

Ken G
1971 280 SL
Silver/red
Ken G
1971 280 SL Silver/red

jeffc280sl

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Re: oil cooler replacement
« Reply #3 on: January 15, 2005, 13:07:58 »
Ken,

Why not consider installing a new hi-efficient oil cooler?  Right now I can't think of a good place to put it.  Maybe that's the same problem MB had 35 years ago. Given that we have almost 7 qrts of oil in our engine a more efficient oil cooler would very likely improve engine cooling.

Jeff C.
1970 280SL 4-speed