Engine Block Coolant Drains

[Bill90Loyale]

To everbody who ever wanted to actually use the nice engine block drain plugs to fully drain the old coolant from your Legacy: Proceed at your own risk, but this was my experience yesterday. This procedure was done on wife's car (I would never risk this with my own Loyale. Just kidding. I've found and used the block drains on the Loyale before). Wife's car is 95 Legacy wagon, 148,000 miles. Drained old coolant from radiator using standard radiator drain plug. Got about a gallon out (capacity is six quarts). Bought a jug of Prestone coolant system cleaner (the kind you put in, add water, and operate the car for about six hours of driving time over a few days). Got tired of looking at those nice two unused engine block drain plugs located on both sides of the oil pan. Went to NAPA. Bought a 14mm hex wrench for $8 (looks like a big Allen wrench). Had car on jackstands. Inserted wrench into engine block drain plug #1. Nice fit. Took a deep breath and pulled. Nothing. No way. Inserted box end wrench at end of hex wrench to gain leverage. No way. Tried using big crescent wrench on hex wrench. Nada. Tried a few hammer blows on the end of the hex wrench. Not a sign. Spotted my three foot long, one inch diameter steel pipe in garage. Inserted end of pipe into short end of hex wrench, inserted other end of hex wrench into plug #1 and pushed on steel pipe. And pushed some more. The hex was bending a bit. Then POP! I looked up, half expecting to see a jagged torn aluminum hole in the bottom of my wife's engine. She would not have been surprised with this result. However, the result was SUCCESS. Same on the second plug (which, by the way, is smaller in diameter than plug one -but still a 14mm wrench size). Drained the Prestone detergent mix which was now Green - proving that there was at least about a half gallon of old coolant left in the system from the earlier radiator drain exercise. Cleaned plugs, one of which looked nice and shiny (the one over cylinders 2 and 4) and the other had that solid old-crap radiator gunk on it. Wrapped the threads on the plugs with teflon tape and torqued them back in using the pipe again (not too much torque now, that tape acts as a lubricant). Flushed system with water, drained it and added new coolant - it took a nice full six quarts. All in all, this was one of the most satisfying experiences in my life. And I'm 51. My wife now has the cleanest coolant in Town. Be brave. Go for it.

[Scottbaru]

I’ll have to look for those. You didn’t happen to note the thread size did you? The stock drain plug in the block of my ‘cruiser is brass, that’s a huge improvement for little $. If these aren’t brass I’d like to put brass ones in.

[JohnnyB]

Nice work, you are braver than me! I did not want to risk stripping them, so I just bought many gallons of distilled water and flushed the system like 3 or 4 times. Glad everything worked out for you.

[NorthLight]

I did the same drain and fill on my 96 outback. Just make sure you keep your pets away from that tasty antifreeze.

[Setright]

For those who are like me and have the irrational-fear-of-stripping-threads disease, try this:

 

Lift the rear of the car so that the rear wheels catch about 6 inches of air. This tilts the engine block far enough forward to let the coolant drain out through the thermostat hole.

 

If you also suffer from I-am-a-bit-nerdy-about-car-maintenance disease, drain all the coolant into a graduated container, just to verify the volume of drained coolant.

 

The tilt system drains all but ca. 400ml of the entire 6000ml capacity

[Bill90Loyale]

I’ll have to look for those. You didn’t happen to note the thread size did you? The stock drain plug in the block of my ‘cruiser is brass, that’s a huge improvement for little $. If these aren’t brass I’d like to put brass ones in.

I did not note thread size. The plugs seemed pretty substantial, but you may prefer brass. You'll just have to measure them when they come out. As I mentioned in my post, the two plugs are of different sizes (diameter). Best of luck.