Need to change the coolant in my 84 SD and want to know how much the system holds?

11 Liters if you drain the block, including the heater core.

per the FSM , disconnect the upper radiator hose at the radiator and
s l o w l y fill untill coolant dribbles out the radiator neck...

*OR* drill the tinyest hole you can in the thermostant flange and fill it normally , then it won't airlock and overheat .

DO NOT fill it partway then try to run it until the 'stat opens so you can add more coolant ! .

That 1/2a$$ B.S. works O.K. on American cars , not so much on Mercedes .

__________________
-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

None of that is correct or from the FSM. NEVER mutilate the thermostat for any reason.

Fill coolant up to level mark on coolant tank.
Start the engine and warm to 40*c.
Push the DEF button on the climate control.
Run engine until thermostat opens.
Check coolant level and fill to level.

Maybe I have a different version of the FSM , mine are the paper ones , not the DVDs .

The OM616 & 627 engines will almost always air lock if you fill them with out the hose disconnected (this is why some years have bleeder bolts on the 'stat housing) and if you run the engine with air pockets , it'll boil the coolant out before it fully circulates and allows you to add more . BT , DT , no thanx .

__________________
-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

In the junk Haynes and Chilton manuals, maybe. My paper FSM shows the exact same procedure as the CD.

Incorrect again, I suggest you get a better manual that has the correct procedures before you damage something following poor instructions.

The early models had the bleeder screw because they were not self bleeding. Later (post-81) models are. You know that round bit sticking out from the t-stat rubber gasket? Yep, thats for the vent hole. Mutilating the thermostat with a drill is useless and counterproductive.

Attached Thumbnails

 

How do you drain the block and heater core?

There is a plug to the upper left of the passenger side engine mount arm. There isn't much that can be done about the heater.

Attached Thumbnails

 

Wow! That was fast. Thanks

Walmart sells the Caterpillar brand I believe. I also think it is the HOAT style. Is this OK?

I also noticed in your profile that you state Alda/EGR removal. What do this do and how do you do it?

Zerex G-05 is preferred in place of actual Mercedes-branded coolant. http://www.valvoline.com/pages/products/product_detail.asp?product=10
As long as its HOAT (Red or yellow) and not the normal green or orange stuff, its fine.

Search, there are several threads on that subject.

If you fill the engine from the expansion tank, coolant will fill the radiator and come up to the level of the thermostat. The thermostat is closed and the coolant cannot enter the head. If you start the engine under this condition, the head will overheat well before the thermostat opens and allows the system to pass coolant through the thermostat and air out of the head.

Therefore, it's mandatory to fill the head with coolant via the upper radiator hose during a complete drain and refill.

So, you think you know better than a few dozen engineers at MB that wrote the book on it?

The upper hose is unobstructed by the thermostat and below the coolant tank level. Its a waste of time to remove the upper hose.

Yes, I believe I do. I've done some extensive tests with the SD.

If you fill the coolant tank to the cold level indicated on the tank, it's definitely below the level of the upper hose.

If you fill the coolant tank to the very top of the tank, you'll get some passage of coolant along the upper hose.............but, it's very slow due to the presence of air in the head.

You can do as you wish.........for all other members..........I strongly urge them to remove the upper hose and fill the head.