Leaking push rod tubes - suggestions???

I just developed a leak in a couple of push rod tubes. Should I replace them or just try to seal them with a high temperature sealer and later replace them during the next rebuild?

If I seal them, what do you recommend for a high temperature sealer? Also, if I replace them, what style push rod tube replacement (spring loaded or threaded with jam nuts) should I use?

Is there a way to re-seat the seals?

TIA