Hose ID

[RICHARD MEZIC]

As a measure of preventive maintenance, I changed my coolant hoses last
week.  While under the hood, I saw another hose that I can't ID.  Under
the hoses running to the radiator and under the turbo after-run pump
there's a hose that is connected to the block.  Fairly large diameter.
Not too long.  My seems VERY squishy and almost flat at one point.  It's
not part of the cooling system.  But it doesn't look like it's part of
the oiling system or the brakes/steering.

Anyone know what it is?  I looked in the Bentley manual.  Various
diagrams show it, but it's never labeled - likes it's included for
reference purposes but not part of the system you're working on.

Anyone?

-RJM-