Hi, I have an 87 300 TDT and the other day an oil cooler line started to leak bad enough I can't drive it. So after some investigation I found that it appears that the line is either rusted or split on the elbow where it attaches to the cooler. It looks as though this is not an easy fix. I can't imagine getting those lines off that engine in looking where they are. So can I bypass? I probably can loop the two together with a couple of fittings and that would be the end of it. I am thinking a couple compression hydraulic fittings to get to JIC and then couple them together. Anyone ever done this? I live in Canada and I never tow or go too far with it anyway so I can't imagine the cooler is all that critical. Does anyone even know the size of the hose or fittings? I had a hard time finding fittings to fit the hydro suspension and they were not cheap. I should mention MB wants $700.00 for the lines. Can the lines be blocked at the engine? Or does it need to circulate? I still would have to take them off but I wouldn't have to put them back on. Any help would be great, I need to decide what to do as I need the ol girl.

Without a picture of where the split is it is difficult to come up with a repair plan.

With the Line off of the Car it might be possible with a Flux Core type welder to weld over the bad area. Or, Heliarc welding would also work.
Both processes heat a smaller area and would be less likely to heat up the Rubber Hose enough to damage it.

Also I do not see why both hoses would need to be replace if the other one is not leaking.

Looping the Hoses together is safer than Blocking off the ports.
There is a thread several weeks ago on the but concerning 617.95* Engines. Some felt blocking the Oil Cooler Ports would cause the Bypass Valve to open and dirty Oil would be circulated through the Engine when the Oil Filter Thermostat opened to divert Oil to Oil Cooler Ports.
I felt that the Manual said the Engine would still get clean oil but neither thoughts have been proven.
And in your case you have a different Engine and the Oil Filtration system may work differently.
So it is safest (or at least gives the closest to normal Oil Flow) to loop the Hoses together.

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84 300D, 82 Volvo 244Gl Diesel

There's a nice thread here regarding an oil cooler repair:-

http://www.peachparts.com/shopforum/showthread.php?t=252254

And there's the big discussion about blocking off the oil cooler lines here:-

http://www.peachparts.com/shopforum/showthread.php?p=2702992

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I am not sure if the Repair info for the 617.95* Oil Coolers is usable on the newer models! The threads on the Oil Cooler Lines and Nippls on the Oil Cooler may be different.

In any event it is his Oil Cooler Line that is leaking "So after some investigation I found that it appears that the line is either rusted or split ..."

There is some US parts dealers selling the pair of Oil Cooler Hoses for $418-$457. Don't know if any ship to Canada or if there would be any extra Duty on them.

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84 300D, 82 Volvo 244Gl Diesel

OK - sorry!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I do it to. I forget not everyone has a W123/617.95*.

In fact the trend on the forum seems to be moving to the 1986 and later models.

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84 300D, 82 Volvo 244Gl Diesel

Well I suppose we'll be wheeled off to the vintage forum in the end...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I actually have the 603 engine, I could repair if I could get the lines off, not sure what misery that would bring. The end by the filter is what looks to be difficult. Anyone know how hard it is to get them off there?

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1987 300 TDT
1990 300 SEL

The lines aren't that difficult to remove on the 617 or the 603. Just take your time, don't get in a hurry, be prepared to get your hands and arms filthy, and just do it.

That may or may not be true. On my 617 one of my Steel Oil Cooler Line Nut was coroded to the Aluminum Nipple. When I removed it I stripped 3 threads off of the Aluminum Nipple.

The cause was a piece of the Nipple Threads stuck in the Steel Nut that acted as a cutter on the other Threads.

Somewher Brian Carlton left some suggestions on how to decrease the chances of that happening.

The sad thing is I do not know if there is a way to repair the Nipples on his 87 300DTD if they strip.
If his Nipples and Line Nuts are threaded the same as the 617.95*s there is a chance it could be repaired using the same method as on the 617.95*s.

He is stuck because it will be easier to repair the lines with them off and if he decided to replace the lines they still have to come off at the risk stripping the Nipples.

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84 300D, 82 Volvo 244Gl Diesel

stripped on which side, the cooler side or the engine side?

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1987 300 TDT
1990 300 SEL

The Aluminum Oil Cooler nipples are what gets stripped.
On the 617s on the Engine Side the Nipples that go into the Oil Filter Housing are Steel.

In fact it is those Steel Nipples from the Oil Filter Housing that are used to do the Repair on the stripped Oil Cooler Nipples.

In your case you only have Threaded Nuts on the Oil Cooler end of the Oil Cooler Hoses.
Seen the black circles in the Pic I believe that is the end that goes on the Enbine Side and it looks like it takes som sort of seals. I cannot tell what it is retained by except that it looks like some sort of Bolt is on each side of the Hose End. Perhaps there is also a clamp for each Hose end.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

Yup, I replaced my oil cooler a couple of years ago because the fitting was messed up. Be careful, the coolers are expensive.

On the 616s and 617s I have done, I cut the hoses off and bring the cooler to the bench. Then I make a cut across the steel nut, being careful to only go as far as I must to weaken the nut. I stick a large screwdriver in the cut and twist to open up the nut, then soak the wound in penetrating oil. So far, haven't lost a cooler in 3 tries.

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

but with the nut gone how do you re-attach? Can a regular JIC fiting be welded on the cooler?

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1987 300 TDT
1990 300 SEL