Oil cooler line thread size
 

I need to remove the oil cooler from my 83 240D parts car to put on my 81 240D. (some fool left a foundation stake sticking out of the ground on my well road!) Anyway, I would still like to be able to move the 83 around the property so does anyone know what size plugs would fit the cooler lines? My hardware stock is metrically challenged so I will need to purchase whatever I need. Any suggestions? Thanks in advance-Scott

best bet is to take the thing to a line shop like napa and have them match it... perhaps make a loop

now that I think on it. your perforated cooler has fittings on it, that can be removed and welded onto something... like each other...

You could unscrew the Hose Fittings From the Cooler and make 2 circular copper or Aluminum Compression Discs that would fit into the tapers inlet of the Oil Cooler Nipples and the Hose Fittings would fit over them and seal off the hole.
They do not have to be absolutely circular just so they seal.

Not real sure about this, maybe someone else will know more.I would not plug/cap those oil lines i believe they need to have oil flow thru them so just make a loop so the oil can flow without the cooler. Don

There is a thermostat in the bottom of the oil filter housing that controls the oil flow and temperature to/from the oil cooler. so there isn`t always oil flowing.

some 123`s don`t have the oil cooler.

Charlie

true, but what happens when the tstat opens?
does it direct flow through the cooler? cutting off the flow otherwise?
on the ones with no cooler, this thermostat would not be there obviously.

On my 603 i believe there is always some oil flow thru the cooler just sitting idling the hoses get warm within about 5 minutes, i suppose the t-stat could be bad.I will have to check the 602 someday. Don

Wow- this is more complex than I thought! The loop makes sense if plugging both hoses would stop the flow of oil when the t-stat in the filter housing opens. Does anyone know if this is actually how it works? If so it seems it would be easiest to get a nipple with the appropriate threads on it and join the hose ends. Or maybe cut off the ends of the hoses (which I would hate to do in case I needed them at a later date) and join them with a barb and hose clamps. Ideally I would like to plug at the filter housing and use the hoses and cooler off the parts car. Would this work?? Thanks for all the help so far-Scott

Maybe plugging the lines as I suggested was a bad Idea. I am not sure if when the Thermostat opens it cuts off the flow of Oil to the filter or not.

The little "a" is the Oil flow into the Filter the Big "A" is the Oil flow past the Thermostat and into the Oil Cooler Hose. The Big "B" is the cooled Oil returning from the Oil Cooler.

So without knowing for sure if the open Thermostat cuts off the Oil to the Oil Filter and sends all of it to the Oil Cooler it would be safer to loop the Oil Cooler Hoses.


http://i242.photobucket.com/albums/f...el911/FILT.jpg

I have read some place about on Benz's that you must not block off the cooler lines as once the motor is hot there is full flow of oil through them.

I studied my factory manual for quite a while last night and I'll be darned if I can figure out whether or not plugging the lines will stop the flow of oil when the t-stat opens. Anyone know for sure? If so, back to my original question- what threads are the lines so I can loop them together? Thanks for all the help so far-Scott

I can only say the theads on the Oil Cooler on my 84 300D are M22x1.5 and it takes a 1-1/16" wrench on the Oil Cooler Line Nuts.

I do not have an 83 240D to check.

If someone can give the part number of the Nipples that the Oil Cooler Hoses attach to at the Oil Filter Housing (the Oil Cooler Hoses should be threaded the same on both ends) I can see if they are the same as the 84 300D ones.
They are also the same sized Nipples that you use when you make the Oil Cooler Repair.
The 84 300D Oil Cooler Nipples at the Oil Filter Housing are #915013-013002.

We used 3/4" fittings. :D :D

http://www.tglmarketinginc.com/mbfor...t/100_2584.JPG