Valve seals tore on break in

There is NOTHING wrong with those seals!
When installed correctly they work EVERY time. And the garter spring? It is a great idea because as the seal wears, it keeps tension on the stem to prevent oil use.

[1] You need to pre-oil the stem & seal [ not WD40, it dries out quickly ]
[2] You need the installation sleeve that fits over the stem; this prevents tearing the sleeve during assy.
[3] You need something that fits over the outer edge of the seal to tap it in place without damaging it &/or separating it into two parts. I made a special tool for this.