I have both success and failure to report.

I went to replace my shut-off valve today. I got the valve unscrewed from the IP but couldn't get it all the way out becase I didn't unscrew the top plate of the IP and swing the ALDA out of the way. Well, I thought, I'll just remove this coolant hose coming out of the block here that is standing in the way of things. The postive: With the coolant hose out of the way the valve comes out easily. The negative: with the coolant hose out of the way lots and lots of coolant pours out of the engine.

So I am reasonably sure that at least a little coolant got into the IP where I had the valve hanging out. Actually, I guess it got into the crankcase, not the IP itself, because there was oil all over the valve when I took it out, not diesel fuel.

So this adds two more jobs to the work list: change the oil and flush the coolant. I had been planning on flushing the coolant at some point anyway since my coolant was green. Just not right at that moment.

So ... the reason why I am posting: here is what I did to flush my coolant. It seems pretty easy. At least easier than removing the engine block drain plug that I only just caught a glimpse of when I crawled under the car.

1. First I removed the radiator drain plug as usual. That got some coolant out.

2. Then I removed the hose that goes from the thermostat housing to the heater line pump on the front of the pass. wheel well (at least I think it is a pump. It has wires going to it and it connects to the mono valve also via a hard line). Tons of coolant came out of this. All of it can be directed down into a bucket too.

3. Then I removed the very topmost heater line coming out of the mono valve. This is the highest point in the system I think. I flushed water through the radiator from top to bottom, then I flushed from the monovalve. All the water and A LOT of coolant came out the hose at the heater pump. I did all this until I saw no more green stuff.

4. Then I put the hose back on the heater pump and flushed some more from the monovalve. The water cam out of the radiator drain. There is a bypass in the thermostat housing that allows this to happen I think.

5. I put the rad. drain plug back in. I filled up the whole system with water from the hose at the monovalve until I saw it fill the expansion tank. This gets the entire system filled with water, right?

The rest is standard: Started up and ran for a while with the heater on as is usually done to let the water circulate. It was getting late so I drove around for a bit and left it there. There was no green tint to the water in the expansion tank that I saw.

Tomorrow I will put in some chemical flush and run it for a while. Then drain everything and fill it up with zerex coolant from the monovalve just like I filled it up with water.

As far as I can tell, this procedure allows you to flush the entire coolant system (heater core and lines, engine block, and radiator) and you don't need to remove the rusty drain bolt.

I ceratinly could be missing something, though. If you think I am let me know so I can fix it tomorrow.

__________________
Jackson

1984 300d 223k
1994 Jeep Cherokee 2.5L 88k

"She may not look like much, but she's got it where it counts, kid. I've added some special modifications myself." -- Han Solo

"Would it help if I got out and pushed?" -- Princess Leia