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Custom loop drain help

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New Member
Jun 24, 2016
Putting together my first loop and I've been hardcore reading stickys and just posts in general. I can't find much information regarding a drain set however. My planned set up is:

Reservoir > pump > radiator #1 > monoblock > radiator #2 > gpu block > reservoir

My plan is to install a y-splitter between either "pump > radiator #1" or "radiator #1 > monoblock" as they're the lowest points in the system. The drain is going to have about a foot of soft tubing that's going to end with a valve.

Can someone shed some light on y-splitters and if there's spots where it's not ok to use them or just any recommendations in general. Thank you!
:welcome: to OCFs.

Give us a list of your PC components and loop to better assist you as well as a diagram of your loop in said case to see where everything will be positioned.
Reservoir: EK-res x3 150
Pump: Swiftech mcp50x DCC
Radiator #1: XSPC ex360 (35mm)
EKWB monoblock/Asus TUF sabertooth z170 s/i5 6600k skylake
Radiator #2: XSPC ex240 (35mm)
GPU: MSI Sea Hawk EK X GTX 1080


Radiator fans: 5 x Deepcool tf120
Exhaust fan: Xigmatek XAF 140mm
Power supply: Evga supernova 850w G2
Ram: Avexier core series 4 x 4gb

- - - Updated - - -

Case: Corsair Air 540

- - - Updated - - -

Fluid wise is also going to be plain distilled water w/pt nuke. Question with that as well. The pt nuke won't be here for another 2 weeks. Would I be ok to run the distilled water without the additives for that period of time or should I wait to recieved the biocide to add the water.

My planned loop set up. The black circle represents where the lines feed into the back of the case and enter/exit the pump. I'd either like the add the y splitter at the exit of the pump and feed one end to the drain tube and one to the rad, or split it at the rad where it's feeding in from the pump and just run the tubing back into the rear of the case.
Sounds like a good idea.

I use this 5-way block at the lowest point of my build when the tubing goes from one radiator to the other. Snuck in a 90 degree fitting on the block and have the drain line connect to a valve towards the front end of the case. Easy to drain.
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Is it ok to add the splitter right at the exit of the pump though then extend the tube a foot before it reaches the valve? I don't want to for some type of back pressure at the pump that could restrict flow or damage the pump.
I don't think it will be an issue but I like to use those straight blocks with many outputs on them, giving you the wiggle room to position a drainage as you may to a valve.

I'd also look at other Corsair 540 custom H20 builds. I know there's a few here and many out there in the web.
I used a Y fitting before. A Bitspower one, and bought a plug to screw in the drain opening. My flow was into the Y umm the upper portion of the Y and out through the single port. I have seen T fittings with a valve on the bottom of the T.

Doesn't matter a lot how it's done, just what works for your case.

FYI, all the water won't drain out. You will still have to tilt/roll/bounce etc to get most of the water out. A drain does help. When it's time to take it apart there will be dribbles etc for sure. Paper towels help a lot. And using distilled water means no goopy dyes all over the place. Distill water on a mobo when it's powered off won't hurt it al all. Just need to dry properly.


So the damn graphics card was larger than I expected. The unexpected studying forced me to make a few layout changes. I think it all worked out for the best. I still need to bleed it more when I get home but I'm very happy with the results. As you can see I split the loop on the pump inlet. For future reference water will not even fill the tube unless you open the drain. I'll post better pics tonight if anyone is interested. Thank you for all the help guys!
Congrats on your build.

A few layout changes I would do is, GPU --> MonoBlock IN --> MonoBlock OUT --> Top Rad (Flipped around, connected to the outer port) --> Top Rad (Inner Port 90 degree fitting through top grommet to Reservoir in the back), Reservoir to bottom pump (Replace Y-splitter with T-line and if I would have known pre-purchase I would have recommended the smaller EK res + DDC pump combo that fits perfectly where your res is sitting now but no biggie), pump to bottom grommet via 90 degree to 90 degree inner rad port on the other side. And you could stick a T-line drain possibly between the two 90 degree connections between the pump to rad.

This what came up in my H20 brain on the fly. You could just leave with what you have but figured simplifying the loop order and getting the right fittings for certain spots and bends for a peace of mind. I don't like that stretch from the CPU to the rear. Almost looks like its going to pop out one day. That stuff gets me nervous so I'll sit random parts of the day brain storming on how to connect it differently.

Overall it looks good but I would just rearrange a few things.
My original original thought process was to flip the top rad as well to be able to sneak the tubes right out the grommet on the right but unfortunately it won't fit there as the other radiator is blocking that from happening. I'm def open to other suggestions I wasn't too sold on how it went from the pump to the CPU either. I just utilized all the fittings that I had without needing to purchase more.
I think the way you have it is ok but without moving the rad as you brought up a good point as I now realized that won't work, my next question is, which side is the in and out on the mono block and are you tight on budget where you won't be able to purchase some 90 degrees and a T-line if it came down to it?
In is on the right side directly over the cpu. Out is on the left headed to the top rad. I'd honestly rather not spend the additional money if not needed. The 1080 already stabbed me pretty good as I bought that at the same time as the loop. I'm not sure how the 90 degree would fit either way as the ram gets in the way at that point. I was originally gonna use a 45 but ran out of fittings quick. I can already see the future burden of draining the y instead of a t. I already have water in there as is so it's gonna need to drain at some point. I'll probably just switch over when that time arises.
Again, you should be fine, just make sure there isn't too much tension on that tubing heading out the back.