Clogged engine block coolant drains? (4 Viewers)

[bignoob221]

So I bought this gx470 and am doing routine maintenance and want to change the coolant. Especially considering I didnt have any records for it and the coolant is a SOLID and THICCC brown and with as much rust particles floating as McDonalds uses in their fries .

When I go to drain the block by cracking those brass fittings on both sides of the engine. Nothing. Not even a slow drip. Since there isnt a good line of sight to see into the fitting when you remove the brass plug. I tried picking at it and its hard as a rock.

I figured that its probably rust and corrosion that has formed over the drain fitting causing my clog. (This old coolant has done more damage to these fittings than I do to my toilet after Taco Bell). But I digress.

The only way I can think of to unclog this is setting my air compressor as high as it goes, and trying to blow this stuck turd up from the bottom.

So I want to ask. Is this a good idea? Is there a better way to fix this? I considered unscrewing the drain fitting to see if its the fitting thats clogged. Or the entire block. But I dont know how to reseal the fitting? It looks like there is a bit of sealant formed around the threads. But Im not sure. Can I just use standard Teflon tape? Paste teflon tape? Coolant rated RTV? So please, if anyone has dealt with this. Or knows of a solution. Please let me know.

Thanks!

 

[SteveH]

@bignoob221 - I would gingerly remove the entire fitting(s), clean/replace, and use PTFE paste when reinstalling. I doubt you'll be able to clear it with compressed air or a coat hanger in place. While you have the fitting out, see if you can't backflush the block from that fitting area (may not be possible, but worth trying).

 

[GXFamily]

Try to use compressed air to blow into the fitting and then see if it will
drain

 

[Stonefoot72]

Mine were just like you're talking about. Like the gentleman above said, I pulled mine completely off and cleaned the elbow tube with dental picks and reinstalled. Problem solved for me.

 

[bignoob221]

Mine were just like you're talking about. Like the gentleman above said, I pulled mine completely off and cleaned the elbow tube with dental picks and reinstalled. Problem solved for me.

What did you use to reseal the drain fitting? I have both Teflon tape and rtv on hand. Just not sure which would be better.

Also, for an update. I used thermocure's rust treatment flush thing. Going to leave it on there for like a month and flush. Will see where that gets me. My last resort will be removing the fittings and cleaning out with a pick or compressed air.

 

[bignoob221]

Also, for an update. I used thermocure's rust treatment flush thing. Going to leave it on there for like a month and flush. Will see where that gets me. My last resort will be removing the fittings and cleaning out with a pick or compressed air.

And a final update for anyone that comes across this in the future with the same issue.

I ended up leaving the thermocure's rust treatment product in the system for about 3 weeks instead of an entire month because I was running out of patience. After draining and opening the passenger side engine drain. I could feel that the plug had soften when I stabbed my pick into it. After more stabbing and scraping. I managed to break through the rust plug and got a slow dribble. After a lot of hose flushing with more aggression picking. I got the passenger side to drain freely. Unfortunately, the driver side drain was still as hard as a rock.

After doing some more research. I learned that vinegar can dissolve rust. And luckily, I had a gallon of high percent cleaning vinegar at home for cleaning. So I threw that in and left it for about a week and a half. I left it for a shorter time because I was again, running out of patience. But apparently vinegar can cause pitting in metal when left for a long enough time. It is acid after all. Amazingly, the driver side drain had also soften up after soaking. But no matter how much I picked, I couldn't break through like I did with the passenger side. So as one last hail Mary, I cranked up the pressure on my compressor's regulator, snaked my air gun up in there, and managed to blow apart the rust plug.

Then it was the usual of flushing until nothing but water came out. Then refilling and bleeding with antifreeze.

I took it on a shake down run and it did get to 213 degrees Fahrenheit. But that was with ambient temps in the high 80's to 90's and while climbing at a rock crawling speed with the AC on. Otherwise, it was solid at 185 to 190's for the rest of that pretty hot day. I'm also happy to report that my coolant has stayed the right color of pink. So hopefully I got out all the rust.

Hopefully my cooling system can live happily ever after.