good "scientific study" on the effects of various cleaners on O-rings (not a good outcome for WD-40)
PART II WD-40 O-ring exposure effect results - ADVrider
Honestly, those results show absolutly nothing....
In order to get any amount of useful data, there needs to be a significantly larger sample size...
under those test conditions its hard to say if it was a bad o-ring, or if it was a result of the solvent or both..
Maybe the control was a particularly strong o-ring compared to the rest...
Maybe the brake fluid a particularly weak specimin...
Point is, a sample size of one tells absolutly nothing about failure rate...
when i do failure analysis like this, counts are usually up in the hundreds of specimins in order to get a usefull statistical probability...
including the control...
most materials don't have absolute failure points, some are stronger, some are weaker...
Just saying...