Yanmar coolant flush and refill

[cardude01]

So I'm trying to drain coolant on my Yanmar 4Jh4-hte and the only drain I can find is under the HE. According to what I've read that will supposedly get 80% of it out but I only got about a gallon out.

Just thought about the coolant lines going to the water heater. Does that WH have to be drained as well? Of course I can't get to the stupid thing.

I can't believe I'm having this much trouble trying to change the stupid coolant.

Is there a trick? Am I an idiot?

 

[LarryM]

There is a block drain on the right hand side of the engine. It is at the same level and aft of the oil filter. See diagram below.

Remember to close it before refilling . . . not like I did one time

 

[MurrayM]

Our 4JH2 has a coolant petcock on the other side of the engine that gets the last of it out.

 

[Capt.Bill11]

Use a shop vac to suck it out. And remember some engines take a while to bleed out all the trapped air after you change the coolant.

 

[cardude01]

Use a shop vac to suck it out. And remember some engines take a while to bleed out all the trapped air after you change the coolant.

Now why didn't I think of that?

Thanks!

 

[Cat Daddy]

I used my oil change hand pump w/ 2 gallon container. The small tube that is inserted down the dipstick tube fit in the short clear tube attached to the block drain behind the oil filter. Did not spill a drop.


Rafe

 

[Nomad Willy]

I used my oil changer also.
Took me some time to find the drain plug in the first place as I seemed convinced it was on the port side of the engine. My engine is a Mitsubishi a bit smaller than the Yanmar.
I removed the plug w little coolant loss and inserted a small ball valve w a hose barb end. Used clear plastic hose of appropriate size to attach to the oil extractor hose. With the system vented above and the valve open I sucked out all the coolant in probably less than two minutes.
I didn't but I probably should have found a rubber cap for the hose barb end to keep the ball valve clean.

 

[cardude01]

Never could find the block drain. Sucked a couple of gallons out with the bucket vac using the HE drain.

Test cruise. No leaks. All good.