om603.971 hose replacement help

[wwii]

I need to replace a Y shaped hose, part number on the hose is 140-832-73-94. It is item 317 on the attached picture. One leg of the hose comes from the bottom of the engine, one leg goes to the bottom of the coolant expansion tank. I haven't been able to trace the third leg yet but I think it might go to the heating system, duo-valve.

Does anyone know where that third leg is connected?
How much coolant should I expect when I disconnect the hose, all of it?

Thanks much

[ROLLGUY]

It should go the the bottom connection of the radiator. Most all of the coolant on that side of the thermostat will come out, or at least the coolant above the level of the thermostat.

[wwii]

Thanks, guess if I just prepare for the max I'll be OK.

I'll look again - pretty sure I traced one to the expansion tank and the third to a hard pipe that snaked around the right side of the engine compartment towards the back where I lost it, seems like a circuitous route to the bottom of the radiator. But then it was cold and dark outside so...


ROLLGUY - is your 1991 350SDL pretty much the same as my 1992 300SD? I'm still trying to figure out what information transfers from one model to another or is similar between models.

[babymog]

The '91 (W126) and '92 (W140) are completely different bodies, the engine is mostly the same (OM603.970 3.5L vs OM603.971 3.5L).

[ROLLGUY]

Originally Posted by wwii

Thanks, guess if I just prepare for the max I'll be OK.

I'll look again - pretty sure I traced one to the expansion tank and the third to a hard pipe that snaked around the right side of the engine compartment towards the back where I lost it, seems like a circuitous route to the bottom of the radiator. But then it was cold and dark outside so...


ROLLGUY - is your 1991 350SDL pretty much the same as my 1992 300SD? I'm still trying to figure out what information transfers from one model to another or is similar between models.

I am almost sure that IF part of the hose connects to the expansion tank, then the other two connections would be the thermostat housing, and the bottom radiator connection.

[wwii]

Went ahead and drained all the green coolant, replaced the hose and refilled with Zerex G-05.

The hose is connected to

1. - a port on the bottom right side of the engine (forward of the block drain),
2. - the bottom of the expansion tank via a hard pipe,
3. - and to the water valve in the front left of the engine compartment (behind the hydraulic fluid reservoir) via a hard pipe (A1408306515) that snakes around the right side of the engine compartment to the back then forward again.