I replaced my oil cooler lines that were leaking. When I went to reattach the lines to the cooler, I noticed the threads came off with the old lines. I did some research here and found a fix that includes cutting threads off cooler, drilling holes out to 21/32, tapping the holes, and installing "screwed nipples" part 915014-013002. I ordered the nipples, but the threads that the nut from the lines go on are about 22mm on the nipple and about 25mm on my nuts (and dethreaded cooler). I love the screwed nipple fix, but does anyone have a part number for the nipples for an 87 300 TD? The 915013-013002 nipples are too small.

Nipple

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The instructions for the Oil Cooler Nipple repair is for 617 engines. So that is also what the part numbers are for.
Which is also all I have had experience on.

That being said the repair nipples for my 617.952 engine are actually the same fittings as the ones that screw into the bottom of the Oil Filter Housing. They are not specially made repair nipples.

Assuming both ends of the Oil Cooler Hoses on your year and model are threaded the same on each end you would be able to go to a parts site that has the diagrams (exploded views) of the Oil Filter Housing and get the correct part number from there.

You will have to find out from there what threads are on it and what size Drill and Tap are needed. There is Tap Drill charts on the internet once you now the size and pitch of the threaded end that screws into the Oil Cooler Housing.

Also if you don't drill the hole and tap it straight don't worry just degrease the threads inside of the oil cooler and the treads on the nipple that will be going inside of the Oil Cooler and coat the threads that screw into the Oil Cooler with JB-Weld the slow curing one as it can take the heat. If you do that you don't need to bother with the Crush Washer which is only going to work if you get the hole straight in and you file what is left of the old nipple flat enough for it to seal.

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84 300D, 82 Volvo 244Gl Diesel

When I did the nipple repair on my Oil Cooler I thought I had washed out any chips.

When I changed my Oil Filter I found chips at the bottom. It took like 6 months for the chips to work their way to the Oil Filter.

The Oil going through the Oil Cooler is unfiltered Oil so the chips blocked by the Oil Filter were in no danger of getting into the engine bearings a so on.

It is just that you need to take a look down there because it is possible to pull up the oil filter the chips can fall into stuff. Be carful.

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84 300D, 82 Volvo 244Gl Diesel

Quote:
Assuming both ends of the Oil Cooler Hoses on your year and model are threaded the same on each end you would be able to go to a parts site that has the diagrams (exploded views) of the Oil Filter Housing and get the correct part number from there.

Thanks Diesel911. The ends of the lines on the oil filter Housing are totally different. They are fastened by two smaller bolts for each fitting. I think I can figure out the exact size and pitch of the nuts on the cooler end, but if Mercedes doesn't have a similar nipple to the 915013-013002 (617 part #) for OM603's I guess I'll need to figure something else out. I do appreciate the responses!

Sounds like you are going to have to invent a repair procedure or obtain a used or new Oil Cooler.

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84 300D, 82 Volvo 244Gl Diesel

It probably doesn't help, but on my 603 powered w123 I chose to keep the oil cooler from the donor 87 300TD. I couldn't get the fittings to behave to I drilled the oil cooler for AN fittings and brazed on AN bungs on the oil cooler hard lines.

That was my solution to the problem you have.

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Onus probandi incumbit ei qui dicit, non ei qui negat

I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]

So your nipples are too small and your nuts are too big ? Sounds like it could be worse 🤡

That said if you can return your new oil lines , this is what I would do — go to a hydraulic shop and get them to make Some lines to fit your nipples.

That’s what I always do anyway cause they are better quality imo. I usually bring my old mb lines and they use the mb nuts and just use new good rubber. This is works good for power steering too. Brazed an fittings are cool too.

Also did you back hold the oil cooler with a big wrench while you tried to unscrew the oil cooler line ? There is a place to put a wrench on it to prevent what happened.

Thanks you guys! I did hold the nut on the cooler. Think the variation of the metals and age of the parts caused the threads to gall and stick in the nut threads. Not sure I could have prevented it. I will have to look at some sort of alteration to the current set up. I appreciate the suggestions.

If the factory had coated the threads with something like never-seeze they would not have corroded to the nut.

One of our member said he though that if you took a Dremel Tool with the tiny cutoff wheels and you split the Nut lengthwise in 2 opposite positions you could spread the nut and split it and would not have to turn it off.

But, no one has tried that.

They make fittings with pipe threads on one end or SAE threads on one end and metric threads on the other but you need to have the same end face. It might be possible to have the metric end made to match the inverted cone of the original if a machine shop did that.

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84 300D, 82 Volvo 244Gl Diesel

For anyone else reading this thread, the number in red above is incorrect. The one in Blue is the correct one.

The seal is N 007603 018101. Worth buying whether used or not!

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

I ordered a couple of the nipples and seals today. Just in case we need them when the oil cooler lines are removed. About C$10/set from local dealer.

I checked and I actually have a 21/32 drill bit! Probably won't buy the 18mm tap until I know we need it.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Well, the bottom nozzle on my 85 was not in the best condition. Threads not stripped, but crest of threads worn off and major diameter reduced. The union nut came off easily. Maybe it could just have been tightened! There had been leakage so perhaps seat was slightly damaged.

Anyway, decided to replace bottom nozzle. Perhaps this may be of interest to those faced with nozzle repair:

Parts:
Nipple fitting N915013-013002
Seal for above N 007603 018101

Tools/Supplies:
21/32" drill
18x1.5mm tap
22mm thin flat wrench
24mm socket
Torque wrench
Permatex High Temperature thread sealant

Method
(My neighbor has a small machine shop in basement!):

I first flushed oil out of the cooler using mineral spirits and Acetone, then blew dry with air.

He set cooler up with nozzle as vertical as possible on his mill. Then
- used a side cutter to cut the nozzle off close to the hex base
- milled the face of the hex flat & square
- drilled the 21/32" hole
- tapped using 18mm tap. (grease on tap catches some aluminum chips)
(all while keeping everything aligned)

I then flushed from top to bottom with mineral spirits. Shook it up each time and poured contents through a coffee filter. Did that 7 times (re-using the fluid( until no further aluminum could be seen. I then did it twice with acetone and then blew dry using air. Looked inside and it looked fine, but being a bit anal, I hooked up small tube to Shopvac and vacuumed as well!

Next installed the MB nipple and crush washer. I first applied Permatex High Temp thread sealant to the threads. Hand tightened. Then used torque wrench with 22mm socket to tighten. For 18mm spark pugs in alloy heads with washers, they use 22ft.lb. Because of sealant, I cut this back and started low (~10ft.lb) and gradually increased. Ended up at about 18ft/lb after washer crushed. (Used thin 22mm flat wrench on the aluminum boss.)

Ready for my young friend to install and connect the new oil lines!

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

replace the rubber parts with SS aircraft hose and use screw fittings so I can change the hose without detaching from the cooler or the filter housing.

Never again will I fight to replace oil cooler lines. I will never face a repair on the cooler or the filter housing. I also put aluminum anti seize on the ends too.

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84 300SD
85 380SE
83 528e
95 318ic

Good idea to make flexlines replaceable. But at same time, I would make the mod of the aluminum nozzles as outlned above. Those aluminum threads are more likely to fail than the lines themselves.

I am saving my old cooler lines with view to having them modified for easy replacement. Mind you, first lines just started to weep after 35 years, so I may never get to that

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5