Water Cooling Problem Leaked 5 times with Thermaltake Pacific M360 Plus D5

May 31, 2018
New to the board, my first attempt to water cool using the Thermaltake M360 Plus Kit. Once the system was complete, I filled the reservoir and let the system bleed (with refill cap opened). Once the air is out, I close the fill port and within 24 hours the system builds up too much pressure and disconnects from one of the fittings. This happens when the pump is running and even when it's not. The location of the leak is different every time. I'm not sure why it continues to leak or builds up too much pressure even when the pump is turned off. Please check out the pictures and tell me what i'm doing wrong. Thanks



Contributing Writer
Staff member
Just from looking at the tubing and fittings, it would appear that you are attempting to force tubing and fittings that are not actually 90 degrees into right angles. I think the real issue here is pressure due to torsion, twisting or leverage causing the fittings to become separated and nothing related to the pump since you said this also occurs when the system is powered off.

Also to add - in your last photo where your CPU block feeds into your GPU, you could have simply made 1 angle and gone into the same 'back' side of the GPU block on the same side as the outlet rather than snaking all the way around to the front port. 90 degree fittings add restriction...and you are adding more than you really need with all those. It would have been better to bend the acrylic tubing (and a lot cheaper than purchasing so many 90's).


Only thing I can think of other than what rubix mentioned is fluid levels. Those are compression fittings, so should be tight, not just finger tight, and if you max fill the reservoir, when the heated liquid expands, it's got no where to go, so the weakest point will be the first to fail.

Radiators are notorious for holding air, even after days of usage, and when the pump is running, that air will be compressed. Turn off the pump and the air will eventually expand, putting pressure on fittings where there shouldn't be any.

I'd recommend leaving at least @2cm of air in the reservoir and make doubly sure all tubing ends are burr free and fittings are tight. You shouldn't be able to give the tubing a decent tug and have it separate from the fitting.
Sep 19, 2018
Adding onto this discussion in case it helps someone who experienced this same issue. I installed an M360 kit and had the PETG pipes pop off the fittings twice now. I was in the room both times and there was a gush of fluid, not a leak, and not due to the pump pressure, which I have at the lowest setting due to no GPU cooling. My pipes are very well aligned so torsion between the pipes and fittings is unlikely. The PETG pipe audibly POPPED out of the fittings which I had double checked.

Air/gas pressure build up is clearly what is happening here. Maybe there is some oxidation occurring in the radiator due to interaction with the coolant. Its also likely the change in temp of the air gap in the pump and or radiator is doing this as well. Karadjgne is right, the radiator takes a while to fully bleed all the air out. In either case, to mitigate this problem I have left the plug on the top of the pump slightly lose to allow for air/gas expansion.

Hope this helps.

Similar threads