Originally Posted by TURBS
They should hold water indefinitely.
Seal may be just dried out or there's debris in the seal silde.
I've never had to replace a seal.
Just had to clean our seal and lube it. People will reference all kinds of things they have used for lube, but in my opinion using something like Plumbers Grease, which is silicone based would be the safest bet so as not to cause seal distortion from a petroleum based product causing issue with the rubber.
I used a product called Sil-glyde we use for lubricating rubber brake components because it is silicone based and rubber safe.