That's weird D&T I never had any issues with the crystal link tubes from Bitspower. The rig I have it on is my main one with crossfire 5870s oced 920 and no leaks thus far.
How much heat were you dissipating may I ask? Also was this under higher pressure than a mcp655? I really don't want to have to break my system down to replace the xfire and northbridge connections.
D&T had a pump failure which caused block temperatures to spike and deform the plastic. I had a similar temperature case where I had a leak empty the loop and cause cgminer to idle the GPUs when they hit 65C. This was with just 4 5970s in serial. Luckily I was using the Phobya links and didn't suffer any plastic deformation. I do agree, if you are in your rig, wiggling cards around you could cause a leak. I've had no leak issues though as I don't touch my watercooled rigs when they're running. That's just asking for a dead mobo.
Yeah to avoid derailing the thread let me provide some context.
1) Pressure is a lot.
2) System is dissipating ~ 4KW of heat.
The bitspower crystal tubes worked fine for years in my water cooled workstation both before and after I started mining. Also I have never had a problem with any of their other nozzles, compression fittings, clamps, etc). When the pump "failed" it actually was still pumping but at a very low flow (guestimating <0.2 gpm) this caused the temp in GPU block to rise. The plastic "clear" part deformed at ~85C. All of the links deformed but only one deformed enough to leak. Luckily it was a "slow" leak and it only killed the motherboard. If your rig never overheats then you likely will never have a problem.
I think Gomeler may be right on the phobya links. I am using a high end aquarium pump (20ft+ of head @ 15gpm+) so that may have contributed to the leak. I was connecting a GPU power connector and pressed down too "hard" (not that hard IMHO) on the card and it must have shifted the link just enough. I got a spray yes a fraking spray of water. When I let go of the card it stoppped. There are not many more things scarier than seeing a spray of water shoot out inside your server.
Amazingly I suffered no damage. When I am doing leak testing I take one sheet of a shop towel (paper) fold it into quarters and then roll it up. Fits perfectly between two cards suspended below the link. I usually leave that shop towel in for 3 days or so to check for any small leaks. I was lucky and the towel absorbed the blast. One of my rigs still uses the phobya links. I am just super careful/paranoid around them.
After that I bought a set of the danger den links and koolance links to test. Both worked and are still in use but by that time I found the Swiftech ones. They are solid. I ended up buying 3 sets for the last 3 rigs.
So 6 rigs
0 set of Bitspower crystal links (trashed them all)
1 set of Phobya SLI links
1 set of Danger Den SLI links
1 set of Koolance SLI links
3 sets of new Switftech SLI links
The Danger Den links are very similar to the Phobyas but looking inside the o-rings are much larger providing a tighter seal.
The Koolance links are very good (likely the best SLI links) but at $15 a pop they are just highway robbery.
I like the swiftech ones even better because they are almost the same as the Koolance ones but they are designed to be tightened with a wrench, have a more industrial feel (function over form) and they are only $8 ea.