Two years ago I had bad cracks in my coolant expansion bottle, so bad that coolant would leak though. I replaced the expansion bottle and after only two years there are already cracks showing. Not as bad as before, it’s not leaking yet however I believe this could still be a problem as the cracks are above the coolant level and it may be releasing air pressure.
My underline questions are should I change it again just to be safe and what are the effects on my engine if I ignore it? Does having pressure in the cooling system really matter? And most importantly can my engine over heat without my knowing.