Hydor L30 reliability

[AINTD]

Has anyone ever had a problem with Hydor L30? I mean, what are the chances of it breaking down? Start leaking all of a sudden? Also, in the manual there's one place where it says that L30 is designed to run at 35C water temp max which is not too high. If I overclock my PC or just put it under stress as it is, it may go over 35C I think; is this a real issue? I like to run my PC silent, with fans running at minnimum RPM's, turning them full on will bring the temp down by a few degrees but this is not the meassure which I like (nor anyone would I believe).

 

[AINTD]

It's summer now and room temp is around 27C +/-. Unless airconditioned water temp is always around some 33C with one core fully loaded (running Prime95) and fans switched to minimum RPM's. Under the same load with fans fully on (plenty of noise) it can get down to some 31C. So, I'm running a bit too close to the 35C mark with one core 100% loaded. I tried loading the second one too and running them both fully loaded for a couple of hours or so, CPU temp rose to around 45C and stayed there, water temp never reached 35C, but was close to it. And that's under little to no GPU load.

By the way, it's a bit an off-topic, but watercooling related question: I made my reservoir out of a plastic can with cap closed by spinning along the thread CW (typical stuff). Can the tank being sealed tightly go wrong? (I mean with water temp rising, increasing pressure, evaporation and stuff like that).