Hi folks..

Did the 340,000 mile service on the 83 300D today. While I was under there checking things out, I noticed the rubber hose that goes from a nipple on the bottom left of the radiator to another nipple on a metal transmission line was starting to dry rot. I presume this is a transmission fluid cooler line.

Anyway, after a lot of searching, I cannot find a part number for this hose. I did find a hose on the Pelican Parts site but I'm not sure that is the hose I need.

Can anyone provide a part number or a link to the part? Also any "gotcha's " to watch out for when I change the hose would be greatly appreciated.

Many thanks,

Glenn

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2012 Mercedes ML350 Bluetec 102K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 238K (mine)
1998 Volvo S70 T5 Turbo 211K (kids)
1994 Ford F150 4WD 246K (firewood hauler)
1983 Mercedes 300D 384K (diesel commuter)

MB part number 019-997-80-82.
Use a counterhold flare wrench when loosening/tightening the transmission cooler lines.

The rubber grommets (112-997-02-81) for the clamps on the metal lines going to the transmission will probably need to be replaced as well..

If the rubber grommets have deteriorated, the metal lines can chafe against the metal clamps and over time cause ATF leaks.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

Many thanks!!

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2012 Mercedes ML350 Bluetec 102K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 238K (mine)
1998 Volvo S70 T5 Turbo 211K (kids)
1994 Ford F150 4WD 246K (firewood hauler)
1983 Mercedes 300D 384K (diesel commuter)

Does anyone know the size flare wrench needed? I plan on picking up a new set and want to be sure I get the right size.

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2012 Mercedes ML350 Bluetec 102K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 238K (mine)
1998 Volvo S70 T5 Turbo 211K (kids)
1994 Ford F150 4WD 246K (firewood hauler)
1983 Mercedes 300D 384K (diesel commuter)

Look under the car and count how many of those little rubber isolators you'll need, I've seen too many steel pipes wear paper thin then squirt all the ATF out leaving you $tranded......

I bought a set of thin metric sized open end wrenches @ Harbor Fright, they're cheap crap but have worked on several jobs now, once you rip the swadjed in nipple out of a good radiator and ruin it, you'll never again loosen and thing without two wrenches firmly held .

They're handy when you change out the oil cooler hoses before they spring leaks as you're driving.....

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

On my W116 300SDs:

The flare nut on the tranny cooler hose is 19mm, the counter hold on the hard line is 17mm.
A 17mm open end wrench will work as the counter hold.
Though a 17mm flare wrench will give a better grip.

The oil cooler lines have 27mm nuts on either end.
As vwnate stated, slim open end wrenches are needed in various areas on our cars.
You can slim down a wrench with a a grinder, or purchase new/used slim wrenches.

My aluminum oil coolers have 22 mm counter holds, and the oil canister nipples take a 24 mm counter hold.

As far as the rubber grommets go, my cars use 3 on each side, for a total of 6 on each vehicle.
Two are on the bell housing, close to the banjo fittings, and 4 are on the oil pan.
Not sure how many you require.

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78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

I replaced the hose with normal transmission cooler hose (7/16"D) and hose clamps. You can just cut off the crimped ferrules to re-use the fittings. But, new hose assemblies are fairly cheap here on P-P.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Bill, was that hose you mentioned 7/16 inner diameter or outer diameter? I tried breaking loose the hose fittings from the radiator and they are frozen tight. So I was thinking on using your idea and cutting the old hose off by the fittings and attaching new hose with hose clamps.

I know it was the same "transmission oil hose" I use on my Chrysler minivans (1996 & 2002), fairly standard 7/16"D hose (recall). I have rolls of various hoses in my garage stock. All hoses are spec'ed as ID. Only metal tubing is spec'ed as OD.

You can use regular screw hose clamps, but if you want a clean factory look, buy Oeticker stepless ear clamps on ebay. You can tighten them with cheap "nail puller" pliers rather than the special tool ($$$). For that, you'll need to measure the hose OD when on the fitting and review the spec'ed range for the clamps. Trans cooler hoses don't carry much pressure since I recall the return just dumps into the tranny pan.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans