Bad install.    You want the hoses on the bottom, so any air trapped ends up at the top of the raditor, not in the lines.

Next on the radiator, mount it on top of the case horizontally with top vents in the case, so any trapped air is on the top of the radiator, so the fans are blowing across fluid at all times,and it's only fluid that is being pushed through the cooler.

Think trapped air.

With the hoses at the top of the side mount radiator for the CPU, your just cavitating trapped air through the lines to the Cpu heat transfer manifold over and over again.

So yes, on the CPU chassis mounted radiator, it needs to be flipped so the  hosed are coming  out of the bottom side.  This keep any air in the system trapped to the top side of the radiator, instead of being cavitated air to the CPU heat transfer manifold over and over again.


On the GPU, you have to remember that the fluid pump is in the GPU heater transfer manifold, so If all the PCI-E slots are the same, I would move the GPU to the bottom slot if possible (may need some 90* fittings).  This insures that any air trapped in the lines/GPU block is forces out since it the lowest part in the cooling system, and the trapped air  in the system ends up at the top of the side mounted radiator as well. If the GPU needs to stay in that pci-e slot, then would think about moving the raditor for it to the top of the case.  This would put the GPU block at the bottom of the system, so any air would be trapped up in the raditor instead.


Really, it just comes down to how far you are going to overclock the system, and how much cooling you need before you get a melt down instead,  
but any air in the system making it way to,or trapped at the manifold heat transfer blocks is a bad, bad thing.  This is why the radiators are always mounted as high as possible in the chassis, and the cooling pump with block the lowest mounted item instead.

Better, but when you fire up the unit (block pumps are pumping), cock the chassis first so it on the back corner (the CPU block at the lowest point), so all the air if first pushed out of the CPU block to the radiator on the front,  then cock the chassis on the front corner so the GPU cooler is at the lowest point of that system, so all the air is pushed from the GPU block to the top of its radiator in the back.

The unit should be fine at this point with any air in the cooling system trapped to the top of the radiators, unless you go to move it, then do the cocking thing again so all the air in the system is pushed to the top of the radiators again.

As for in the future, just remember that you want the cooling blocks on the CPU/GPU to be at the lowest points of the system, Hence so any air in the system is natural pushed/rises upwards to site dormant in the top of the radiators.  Right now, the CPU has a good chance of self clearing any air to the top of its radiator, but the GPU lines angle down off the block before they get to the radiator is one huge air trap in the lines instead.