For those considering replacing their leaky Cobra hydraulic jack, better to replace the seal than deal with the cheap replacement that does not really fit. At least that is what I found with the Harbor Freight solution. I think it does not have the same stroke as I recall. I replaced mine about 8 years ago on now a 20 year old bottle and still working fine today.

Cost $5.42

http://www.mcmaster.com/#mechanical-seals/=ekh96p

part number 9505K82

Buzz Graves