I have an aux oil cooler connected to original cooler using sandwich plate adapter.
im wondering how to remove all if the oil in the lines ans the cooler. i also have the deeper tuna can thing-
- should i just drain oil like usual? or is there a way to remove the addition oil held in the cooler?

thanks

Phil

With an external oil cooler you never get all the old oil out, so don't worry about it. If the oil is contaminated by something, that's another story and you'd need to remove both oil coolers.

I set mine up so I could disconnect one of the hoses and drain the cooler that way. It might not get ALL of it, but should get most of it.

Porsche had no easy way to drain the external cooler oil on the 911 SC and Carrera. I don't believe it was common practice to disconnect hoses and blow the old oil out.

Improvise:


I have another version made from pressure cooker that works well.

I flush the lines with 5 quarts of the cheapest oil I can find at walmart.
Then I push through just enough of the good stuff that I see the color change as I push it out.
Then I cap it and install the engine.

On my 6 conversion, I installed a downstream valve and safety wired plug. I agree with Kieth as to not getting all oil out (unless the front oil cooler is at 180 degrees or hotter and opened up in the system).... ouch!

Change oil in the presence of Magnolia Grandiflora blooms..