CarQuest Premium 84356 w/5k miles, cut open

[ZeeOSix]

The bypass valve spring was still pushing hard on the little black plastic piece.

Why wouldn't it ... steel coil spring under compression shouldn't ever fail.

 

[gasman556]

Why wouldn't it ... steel coil spring under compression shouldn't ever fail.

My comment was moreso to reinforce the overall build quality demonstrated here which should be the standard of the industry overall versus the trash being peddled by non-PG owned labels currently.

To further your point, it seems the cycling of the spring is what causes fatigue - not remaining compressed. Creative minds can figure out other use cases where this old wive’s tale should be discounted.

 

[ZeeOSix]

My comment was moreso to reinforce the overall build quality demonstrated here which should be the standard of the industry overall versus the trash being peddled by non-PG owned labels currently.

To further your point, it seems the cycling of the spring is what causes fatigue - not remaining compressed. Creative minds can figure out other use cases where this old wive’s tale should be discounted.

Fram tested their coil spring operated bypass valve to a million cycles and they never fail. No bypass valve with a metal coil spring should every fail in use ... that's what my comment was basically about. Never seen one mechanically failed bypass valve every posted on this forum.