A few years ago I won a contest sponsored by F5 Networks and used the winnings to build a new water-cooled PC. Being as it was (and is) my first foray into water cooling I decided to go with an all-in-one unit to simplify matters. After research I decided to buy a Koolance PC3-736BK. A few years of mostly problem-free operation later it started making some gnarly grinding sounds. Looking into them I discovered that the reservoir had, apparently, sprung a mighty leak.
I shut off the system and tried to determine the source of the leak. Finding the inside of the case drenched in (thankfully non-conductive) coolant I saw that the source seemed to be the top of the reservoir. Visual inspection of the top of the system showed evidence of cracks/leaks around the gap where the reservoir mounts into the cooling system and the appearance that the reservoir lid had been disturbed. The system was rather a pain in the ass to disassemble but once that was done and it had drained I could see that the reservoir had indeed failed.
I called Koolance support only to find that replacement reservoirs and pumps for the PC3-7xx series are no longer available. When the subject of warranty was raised I acknowledged that the device was certainly out of warranty – the term is a mere one year. I was also told that the pumps “almost never” fail, so it was probably just a leaky reservoir. My only options were to 1. fix it myself, 2. get a standalone reservoir & pump, or 3. get a completely new drop-in cooling system – the new version of the cooling system from the PC3-736. Option one was cheapest but, with the amount of leakage I saw, least viable. Option two would have significant cash outlay and lose me the use of the power supply and temperature monitoring circuits – a significant part of the benefits of the system. Option three cost over $200.
With those options in front of me, I chose to disassemble the reservoir and see what was what. As I was rinsing the coolant residue out I began to see pieces of plastic floating and swirling around inside, both black and clear. With each rinsing, more residue came out and the problems became more clear. Once the damage inside became obvious I had the opportunity to look at the external damage. The lid of the reservoir was cracked about a third of the way around, mostly around the seam where it was epoxied shut, but in the corner the cracks went through the thick plastic of the lid. That amount of damage took a good amount of force. Internally, both pumps seem to have torn themselves to pieces. One was thrown askew on its mounting pin, leaving serious damage both around the pin and the mounting between itself and the coolant outlet port. The other had blown out the entire pump face where it mounts to the inlet which was connected via hose to the radiator. You can actually see the pump impeller from the face of the pump where it had been blown completely off.
If you look at the pictures, you can see a number of things. Loose pieces of clear plastic…
Broken but attached pieces of clear plastic…
Large pieces of black plastic (some of which are curved, likely from where they mounted to the water inlet/outlet), and lots and lots of tiny pieces of black plastic dust.
You can also see the broken casings of the pumps themselves.
Those motors must have absolutely destroyed themselves – or at least one did and took the other with it. I would call it explosive failure to have generated enough pressure to crack the lid of the reservoir like it did. The two pictures of the entire thing still mostly-assembled also do a decent job of showing somewhat the leakage that had resulted. Look for the crusty, reddish-brown crud at the bottom of the reservoir and on the clamp.
Believe me, there’s a lot more crap where that came from.
On calling Koolance back to tell them what I’d found, I was essentially told, after being put on hold for a while after they’d heard my story, “huh.” No “mail it to us and we’ll see what we can do for you”, no “let us see if maybe a mechanical fault caused the problem”, just that a piece of debris must have caused it. Well, I agree with them. Since the system has been operating as a closed loop since I bought it with the exception of topping off the coolant every four months or so, the debris must have been in the loop from the start, likely as a functional part of the system. Since the clear plastic is nowhere near as pulverized as the black, I think one of the pumps blew itself up, threw shrapnel around, and indirectly took out the other. Depending on how quickly the entire thing took place, it could have been either or both that generated the pressure that cracked the lid.
All I know is at this point, I need to get a new reservoir and pump to get my desktop back into operation, and it’s bloody unlikely to be Koolance parts I use. I’d suggest anyone else thinking about one of their all-in-one units think long and hard about about my story. Think about the availability of replacement parts in the future should one decide to go nova.
