Location of Engine Coolant Drain?

Need to replace my coolant hoses (because they're rubber...) but haven't been able to locate the drain petcock on the engine itself. I know the radiator one is on the drivers side at the bottom corner. My scan of the TM-20 hasn't helped, nor have any of the searches I've tried. Is there one? There has to be, right?

Appreciate any help you can provide as to the location or method for draining the engine coolant.

Thanks!

I don't think there is one. If there is it may be inaccessible, behind the motor mount.

There are two of them, one on each side of the block.

Probably not worth trying to remove during a normal coolant flush, though.

.

So, can I get most or all of the coolant out by draining from the radiator? That'd be great if its that easy...

Yes

You will not get it all. But, you can flush the block out with a garden hose. And then account for the 1-2L that stay in the block when you mix up coolant.

doghead said:

Yes

Click to expand...

Doghead, I just clicked on the link that comes with your comments. Thanks for sharing it, I've been needing a place to answer some questions I have like that.

Well, here's what I did and what happened.

Connected a hose (3/8" fuel hose, to be exact) to the radiator petcock. This hose was slightly too large and leaked, but only very slowly (drip.... drip... drip...). Drained the radiator and ended up with ~3 gallons of coolant. I replaced the upper radiator hose without issue, maybe 1/4 cup was trapped in one of the bends, and I used a tupperware container to move that to my drain container. The lower radiator hose held quite a bit more... several cups. That just spilled everywhere... oh well.

I once I had the new hoses put in, I tried running the engine for 30 seconds or so, thinking that perhaps the pump would move the engine coolant into the radiator where it could be drained. This was not the case... nothing new in the radiator. I didn't want to overheat the engine so I turned it off. Re-filled the radiator with the garden hose and by then it was dark and I was late for something, so I decided to continue with the flushing another time.

Question... according to the CUCV wiki article, total capacity is 25 qts (=6.25 gallons), so I take it either I was extremely low (didn't look that way based on the reservoir, which was about 1/2 full). OR, the engine holds about 3 gallons of coolant on its own.

Tomorrow (or maybe Tuesday... my next day off work) I'll continue flushing it out, which I suppose looks something like.

1) drain radiator.
2) fill radiator with garden hose.
3) run truck for several minutes.
4) repeat until step 1 comes up clear.

I had bought a bottle of "Radiator Flush" ... stuff... anybody think this is a bad idea?

Feels so good to have another few crackly rubber parts replaced with all brand-new stuff!

Hmm... it occurred to me that if I knock out one of those freeze plugs to install the block heater, I'll probably have 3 gallons of coolant all over the ground. Maybe I'll park down the street and do it there... :-/

(I'm an environmentalist and a chemist... if I spill any coolant I'll spill tears too)

Oh, I suppose the smart thing to do would be to flush til I've got nothing but water in there... then it won't matter if it spills! Success!

<end stream of consciousness>

When I change or flush the coolant system I usually drain the existing, fill with water, run the engine, repeat at least one more time. Now you should only have water left in the system, drain it, close the drain valve. Only some trapped water should remain. Fill the required full strength antifreeze first- in this case ~3 gallons, then only add water until full and you should have the correct 50% concentration in the truck. Tips- try not to run the engine with nothing in the system as the water pump need the fluid for lubrication as well as the possible over heating issue. Those radiator flush solutions, if they actually work, may cause new leaks to appear as they flush out crud that was preventing say a head gasket from leaking will now leak.

OK, I just got around to finishing this project (since it's starting to get cold). Radiator flushed, winter thermostat installed, but I've run into some problems with the freeze plug.

I was hammering away at it with a screwdriver, punched a hole in it, drained all the remaining coolanty water... but despite a few hours of hammering I couldn't get the stupid thing to budge. Now it's got a huge hole in it and I can't drive anywhere.

How do I get this freeze plug out? I need some creative ideas.

(Am doing this to install a block heater)

Remove the left FT wheel and use a long piece of threaded rod, round stock or a 3/8 extention you don't care about, go through the fender well and tap the edge of the plug close to the block. Don't hit the block, just the plug. It should spin if enough to grab the plug with a vise grip or channel lock plyers. Tap easy, don't hit it so hard you send the plug into the block, you will have to fish it out.

never heard of knocking out freeze plugs to change coolant.....?

He's not doing it just to change the coolant. He's installing a block heater, too, and it needs a flush, so it's all getting done at the same time.

Thanks Wayne, will try this tonite. Hoping for another nice afternoon. Hadda wake up at 5 and take the bus/subway 1.5 hrs to work today (groan). It's a 20 min trip in the M1009.

I was using a screwdriver and coming up from underneath... hitting not the edge-edge, but the edge of the center indentation, and the screwdriver went right through it without the plug budging. I'll try something longer so I can get a better hammer swing at it.

Hea wired, I have a simple trick for flushing coolant. Drain coolant. Take two 2in X 2ft lenths of PVC pipe, glue on a 90deg elbow. disconnect top rad hose from rad side, Attach the PVC to the hose with the open end pointing down. Fill radiator with water. Run the engine. The thermostat will open discharging the flush water. Slowly add water to the radiator as the thermostat opens and closes. Flush untill the water is clear. You can use a container placed on the discharge end to collect flush water and dispose of it. Unlike flush kits, which discharge water out the rad cap, this method keeps the engine dry by discharging water away from the fan.

Thanks all. Here's what I ended up doing yesterday (it rained for 3 days so I had to wait).

Bent the crap out of the aluminum rod I'd bought for this purpose. Pro tip: Use steel!!! Hunted for some kind of steel rod I could use and found the crank that goes with the truck's hydraulic jack. This thing worked perfectly. I went through the wheel well like everyone suggested, but with the steering wheel turned all the way to the right, I didn't actually have to remove the wheel to get a straight shot. The rod went right through a hole in the frame. After hours working on this, I can barely describe the joyous feeling of having a clear shot at this rod, which didn't bend, and just hammering the F*** out of it (two thwacks and the freeze plug was out).

Since I had previously put a hole in it with a screwdriver, I tried threading a coat hanger through to catch the plug so it wouldn't get lost. I was so overzealous with the hammering that the coat hanger fell right out, but I didn't have much trouble fishing the freeze plug out... it was right underneath the hole and I was able to grab it with some vice grips and yank it out with little trouble.

Flushed the whole coolant system with about 20gals of hot water until it was all running clear, then installed the 600W block heater and filled up with coolant. And now, with any luck, I won't have to touch the cooling system again for years. (knock on wood).

Hey, do us a favor? First really good cold night when you use the block heater, give us a report on how well it works.

@Marcus: When doing my research for this project, I ran across many other commentors who sing the praises of block heaters. Last winter in Chicago was somewhat mild (for Chicago), but despite a few below-zero (Fahrenheit) days my M1009 never faltered. I still want to have some insurance against a really cold day though.

I promise I'll let y'all know how it works out.