hairline crack in coolant reservoir

[jenksy0198]

HI all, having previously reported on the hairline crack in the oil filter plastic cup holder that resulted in massive and sudden oil loss albeit at low speed with a cold engine which thankfully didn't result in a lost engine, I have again experienced the same issue but this time in the coolant reservoir.

Looks like the same kind of plastic material but I could not testify to that, however I knew I was losing coolant slowly and on closer inspection the garage has determined a hairline crack in the plastic reservoir  vessel. The car is 19 years old this year but you don't expect such structures to fail in my case with with two, oil filter holder and now the coolant reservoir it does look like the these plastic parts are suffering under pressure cycles for sure. Does any one else have any similar experience, as I cannot see any other contributor to such failures, no sunlight exposure, no impacts, just pressure cycles?

 

Looking forward to the experience share.

 

Paul