Draining the cooling/heating system.

[artvonne]

  Freezing temps are just around the corner, and im getting squeezed. Currently the cooling system is mostly water, and I have to decide what I will do. I want to pull the engine at some point, hopefully in the coming winter months, so putting 10 some gallons of antifreeze in only to drain it later seems dumb. And with everything thats been going on, I still dont have any books on this beast. Any help locating all the drains would be of great assistance. Im sure I can find them all if I hunt, but I sure as heck dont want to miss any.

[bevans6]

Actually fully draining the cooling system is very hard.  Getting all the coolant out of the lines and the block/oil cooler/heater cores will be close to impossible.  I would put antifreeze in, personally.  The master drain on my MC-5C is a pipe plug in the coolant line that comes to the bottom of the water pump from the passenger side radiators.  There are drains in the block in a number of places, mostly with frozen in pipe plugs in them, some behind the engine cradle that you can't get to anyway, there is coolant going to be trapped in the thermostat housings that won't drain, there is a drain plug on the bottom of the oil cooler, I have no idea how to fully drain the OTR heater core or the drivers heater core.

I would spend the $100 on cheap antifreeze, personally.  I drained mine into a big Rubbermaid type storage container and put it back in when I re-installed the engine. 

Brian

[artvonne]

  The truth is, the circumstances of the last two weeks have ran us very short and $100 of antifreeze today is tight. But I certainly cant afford to watch it get destroyed either. A week or two from now will be a different story, and it may not freeze before then, but I dont wanna bet on it.

  I dont believe it needs protection below zero degrees down here, and if it were protected to zero (the record low here is around -10F), I dont think it would bust anything even if it got colder , just turn slushy??. I just need to protect it for a while while it sits. Ive asked before, and no one ever seems to know, but can RV antifreeze be used?

  Brian, your likely right about rusty frozen plugs, but your live in salt just as I did in Minnesota. This is a southern Bus, little to no rust, and things may not be so frozen. I would much rather just drain it.

[skihor]

Like Brian stated... You can't get all of the coolant out. Putting in antifreeze is mighty cheap compared to the possible conseqences. My system holds approx. 16 gallons, 8 gallons of antifreeze protects down to -40* F.
You might get by with 3 or 4 gallons... I would protect down to -10* F based on your statement. Also, around here anyway, full strength is cheaper than 50/50. I drain, then refill with 1 of each, (distilled water/antifreeze), until full. Then run until the heater blows heat.

Don & Sheila

[bruceknee]

If you are not going to run it, RV antifreeze should work to protect from freeze but doesn't work with heat, way less expensive for your needs, just a thought

[artvonne]

  If the capacity is 16 gallons, I need 35% to protect to -10, almost 6 gallons. 4 gallons will only get me down to 10 above, I dont think thats enough. I guess I may as well bite the bullet.

  On another note, is there a sight glass somewhere on the header tank? Ive looked but havnt seen anything.

[bevans6]

There should be a level glass dead center in the middle of the header tank, above the fan drives.

Brian

[artvonne]

  I see a small copper line coming out the side of the tank between the fill line and upper radiator lines, going to a valve, that has a drain line. There does not appear to be any sight glass anywhere. It appears you open the valve and let it drain off, which would set the level, then close it to retain pressure???

[skihor]

That's how my 5A is set up. I put a water bottle under it and open the valve. When checking later after running the line retains some so be sure to fill the water bottle halfway then you can be sure your level is correct. Then I just pour it back in.

Don & Sheila

[Fred Mc]

I think even a small amount of antifreeze will stop it from freezing and breaking things. The coolant will get slushy and not circulate but won't freeze solid.