Radiator flush

**Forkster** · 06-10-2008, 08:07 PM

Anyone ever do one?

**billr99** · 06-11-2008, 06:19 AM

Yep, just did it last week. I don't do anything fancy as long as I don't see any crud in the coolant and I didn't in this case. So it was a simple dump the coolant with the engine off, re-fill with clear water (I use tap water as my well water is pretty decent as tested), restart engine with water flowing from hose continually until water runs clear. Turn engine off, close taps, and re-fill with properly mixed coolant.

I change out my coolant every 2-3 years and I've never had a problem with this procedure. I will add however that as I do this relatively often the water from my hard-rock drilled well does not create a problem with any kind of mineral deposits. Advantage of pulling water from the Canadian Shield, I guess. When I have lived in places with hard water, either from a well or municipal system, I've used processed water to flush. In this case, I would dump coolant, close the taps and re-fill with just water, then dump it again all with the engine off to conserve the water a bit. Still works OK, just a bit harder effort and a bit higher cost thanks to having to buy decent water.

**Forkster** · 06-11-2008, 07:53 AM

Thanks for the info Bill. Does anyone have a PDF from VADIS on this procedure?

**billr99** · 06-11-2008, 09:41 AM

Pretty basic really. Rad tap is accessible by a hole in the bottom shield on the drivers-side, lower corner of the rad. You will need a deep 13mm socket (not sure on that size, might be 14mm) and no need to pull the plug entirely as it will start running out when you've unscrewed it enough. Block tap is at the back of the motor slightly right (passenger side) of the mid-line of the car. Be a bit careful with this one as it is screwed into a pipe rather than the block itself. A bit of Deep Creep or Liquid Wrench might be in order to free it up. Then as all your coolant drains all over you, you are all set.

Frankly I usually don't do the block tap and cheat a bit by assuming a certain amount of clear water is retained in the block once the rad tap runs clear. Then I adjust the coolant mix by throwing a quart or so of straight antifreeze in first. I then adjust accordingly by just measuring the specific gravity of the coolant to get the right percentage. In this regard, it is probably easier just to crawl under the car and open the block tap too, let both run clear, then close both and re-fill the system. Since I do this in my driveway, I'm just not keen on having coolant run all over me. Obviously, you should use suitable containers to catch the old coolant so it can be taken to a recycler (if you are so fortunate to have such a thing).

Hope this helps

Bill

**Aviator** · 06-11-2008, 03:32 PM

but I flush my gravel driveway throughly with fresh water and regular green coolant will break down with enough fresh water introduced.

Better Google what's in antifreeze, Bill !!! It's not as innocent as you make it out to be !!

Dave.

**billr99** · 06-11-2008, 08:59 PM

Absolutely. Do not dispose of old coolant carelessly if you have small children, animals, or any other creatures about that might some how ingest coolant that has been carelessly dumped on the ground. Renal failure can occur with possibly fatal results.

**Omega5** · 06-20-2008, 07:15 AM

You say properly mixed. What is proper? 50/50?

**billr99** · 06-20-2008, 11:42 AM

According to the "green stuff" jug, max freeze protection (-64C to +135C) is a 70/30 antifreeze-to-water mix but a 50-50 (-37 to +129C) will get you down far enough in winter protection for you folks down south. We see -35C at least once or twice a year up here so I tend toward the 70-30 ratio.

**mbsl98** · 06-20-2008, 02:03 PM

I have found that I never get anywhere near the full content of the system drained through the radiator plus engine drains. As a result, I don't trust running fresh water through it and then refilling with pre-mixed. The risk is that there is a significant amount of water that will now dilute the pre-mix, and I don't know just how much that is so I can't compensate with a stronger pre-mix. Remember that there is an upper as well as a lower limit on the proportions. Anyway, I usually just change it often enough to not worry about getting all of the old out, and refill with all pre-mix - no plain water. I use a 2 year cycle doing it ths way, and it is always fresh looking when it drains out. It is possible that the newer systems drain better, but I haven't done the '07 yet to find out.

**Forkster** · 07-07-2008, 09:39 AM

Originally Posted by billr99

Pretty basic really. Rad tap is accessible by a hole in the bottom shield on the drivers-side, lower corner of the rad. You will need a deep 13mm socket (not sure on that size, might be 14mm) and no need to pull the plug entirely as it will start running out when you've unscrewed it enough. Block tap is at the back of the motor slightly right (passenger side) of the mid-line of the car. Be a bit careful with this one as it is screwed into a pipe rather than the block itself. A bit of Deep Creep or Liquid Wrench might be in order to free it up. Then as all your coolant drains all over you, you are all set.

Frankly I usually don't do the block tap and cheat a bit by assuming a certain amount of clear water is retained in the block once the rad tap runs clear. Then I adjust the coolant mix by throwing a quart or so of straight antifreeze in first. I then adjust accordingly by just measuring the specific gravity of the coolant to get the right percentage. In this regard, it is probably easier just to crawl under the car and open the block tap too, let both run clear, then close both and re-fill the system. Since I do this in my driveway, I'm just not keen on having coolant run all over me. Obviously, you should use suitable containers to catch the old coolant so it can be taken to a recycler (if you are so fortunate to have such a thing).

Hope this helps

Bill

Anyone have pictures of the rear bolt on the pipe? I can't seem to find it.