Right after fixing another problem with one of my cars ( 98 Mazda 626 GF 2L ), I revved the engine and all of a sudden heard the tell tale hiss of a coolant leak:
As you can see, this hose just sprang a leak. Not a big deal, it's probably the original hose, and almost 18 years old.
However, I've had three different hoses go like this in a short period of time, just a few hundred kilometers of driving ( all on the hot side between the heater core and radiator ). Now, I've already replaced the thermostat, which was stuck shut and to which I attributed the previous two hose leaks, but this new leak has got me worried that maybe something else is causing pressure build up in the system.
There is no noticeable overheating, and I'm using a 1.1 radiator cap ( WSM calls for between 0.95 - 1.25 ).
Can I reasonably attribute this to old hoses and coincidence, or should I be looking for some other problem?