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Time to Flush that Liquid Cooling System

Is One Brand Better Than Another

Simple Answer is yes. Although almost every brand is very similar, the percentage of additives that each manufacturer puts in their fluid varies. Some even add UV dye and are available in multiple colors, however the most common is a green color. Of course, this is the same with tubing. The additives in the coolant may make it more efficient, which is good, but it may also make it conductive, which is very, very bad for your computer if you LCS goes kaboom and starts to pump coolant all over that pretty little GTX480. The trick is trying to balance the good and the bad; find a mixture that cools well, is safe for your computer, and prevents mold and algae.

Steps To Changing The Fluid

This process is going to be helpful if you have not changed your fluid in a long time. It will be very dirty and need to be flushed. The steps are quite simple when it comes to changing your coolant. The first step is to gather your tools. Depending on how you attached the tubing, you will need tools to remove the clamps, You will need replacement coolant, a funnel to pour the replacement fluid into the system, a gallon of distilled water, and a large pitcher or something of the sort to catch the liquid. If possible, you should find a friend, with no social life, that knows a computer better than he knows a Friday night out with friends, to help you in case the liquid goes haywire. Luckily, I have an entire staff of them…

If you have a molex power supply, it would come in handy here as well. You need to find and unplug the molex connector that powers the pump for the LCS. Your computer should be off, so leaving it plugged in is a bad idea. You will be attaching the molex power supply to this and using the pump to flush the system. The best thing to do is integrate quick release valves into your LCS from the initial installation, or this part becomes much more difficult. You need to hold the bowl under the point you choose to release the tubing. It is recommended that this is done as close to the outside of the case as possible. It’s not a good idea to release the tubing at, or close to, the processor. It should become apparent why in the next part of this step. You have to release the tubing at the last portion of the system that pulls fluid back into the radiator of the LCS, and allow the fluid in the tube to flow out of the system, into the pitcher that you have.

Molex Power Supply Quick Release Valve

You will need to remove the fill cap on the reservoir, and place the funnel into the hole. Have your friend hold the pitcher and the tubing to avoid any spills onto the computer. Plug in the molex connector to the power supply so the pump begins to pump the fluid out of the tubing. Begin to pour the distilled water into the reservoir, slowly flushing out the coolant and replacing it with the distilled water. I personally do this with the entire gallon jug. It will provide a nice and clean flush of the lines, and the color will tell you if there is anything else being flushed such additional algae or mold off the sidewalls.

The next step is to look at the tubing. The constant changing of temperature from hot to cold and back can make the tubing brittle and start to leak. Even if there were no leaks before changing the fluid, leaks may form from movement of the tubing during cleaning. It’s always better safe than sorry. If you have the time and supplies, replace the tubing when you clean the coolant.


Similar to flushing the coolant out of the system, you will need to flush it back in. For this to be effective, you will need to buy about four times as much coolant as you would normally put in the system. You want to basically dilute the water with the coolant, and although it won’t be 100% flushed (theoretically), it will get close enough not to make a difference. Once you have done this, make sure you hook up all the lines and that there are no leaks. Let the system run for a few minutes, while checking the lines for air and leaks. Softly flicking the tubing will move air out of the lines and through the system. You want to make sure all of the air is out of the system, as air pockets can drastically affect performance. I typically allow the LCS to circulate for about an hour after removing all air, to assure that there are no small leaks.

New Coolant from ThermalTake Coolant after three months of use

Same coolant was placed back into the system as was taken out.

Lets Bring It All Together

You need to change your coolant from your LCS on a regular basis. Some say every 4-6 months, others say once a year. You can be the judge. The images shown above are of the dirty coolant that only had 3 months of use under its belt. The fluid went in looking clear, consistent, and clean, and came out looking like some sort of disgusting dark urine. If you are okay with that running through your system, feel free to let it go. I on the other hand will be the one spending the $22 every three months to give my system a good cleaning. If you have any questions or feel that I’ve left something out, feel free to leave a comment below.

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