Greenish unknown substance stuck to the inside of my tubing

[Jedda]

Now that I'm thinking of it, I'm pretty sure my rad is aluminum. That would definitely explain corrosion.

Right now I'm seeing a vivid mental image of a veteran mechanic covered in engine grease saying, "Now there's your problem."

Missed the Skoda bit in your sig before.

[IanY]

Given your equipment, I would suggest cleaning your loop and getting yourself a cheap MCR rad. Use Hydrx if you like the green color. If you hate green, then pile on the biocide That would solve the issue once and for all.

[initialised]

Missed the Skoda bit in your sig before.

I've got one of those but it's not installed yet, I'm going to use it to cool the hot side of some peltiers.

As I understand it after some use (seperately) both the Al and Cu will passivate from exposure to oxygen but when combined in a system you get a battery effect which allows electrochemical erosion to take place. If you measure the voltage and apply an opposite voltage you stop the corrosion, grounding the components should work but not quite as well. DI water helps as it doesn't have many free charge carriers.

[Jedda]

Yeah the cation exchange value of the solution. Just like soil testing.

[ElEctric_EyE]

We need to come up with a flush system using another pump, so we don't have to dissasseble everything.

[ElEctric_EyE]

I'm starting my cooling system and anticipate these very same issues. I want an easy solution because I am NOT going to tear down my system every 6 months for cleaning.
I think I may have an idea. I plan to implement it into my system when I can find some cheapie pumps for <$50.

You would actually use two pumps. One to suck the old fluid out, and one to pump the new mixture in. You would do it while the system is running without actually disturbing the existing hoses. Just slightly modify your reservoir with two fittings and a pickup tube and two caps for the fittings(when not flushing). I'm using a Swiftech MCRES.

At our shop we use a power steering flush machine with the same idea. We just stick 2 tubes in the power steering reservoir with the engine running and after the flush machine goes through two quarts of clean fluid, the fluid in the reservoir looks like new. This setup is abit different here though because you have two 500 ohm potentiometers which control the In and Out pump speeds. The idea is to start both pumps out at the slowest setting and slowly increase both pump speeds while keeping an eye on the reservoir so as to keep the reservoir at the desired level without running it dry or overfilling. I wouldn't anticipate using more than 2 quarts here either. Think about it, you could also come up with a flushing solution. Let it circulate for how ever long you need, then put in the final fluid. Just an idea...

Here's a quick sketch I made: