Hydralic cylinders have teflon seals and o-rings that seal in the housing. Usually have a spanner nut ato the top of the cylinder you unscrew to dissemble the cylinder push rod. There no reason you can't reseal it other than if you can't find the right size telfon seals and o-rings. Again the age of the jack most likely the seals become harden and alow fluid to seep pass. any type of additive the will cause the seals to soften and swell up may revive the old jack. If and when you do get it resealed now you have to bleed all the air out. which is pretty hard and takes awhile. If the pump rod is pitted form years of contamited fluid it still may leak. If you want something to last for even then you have to have a routine maintenance schedule. On the jack this would be a good cleaning every couple of months, greasing the pivot points and changing the hydraulic fluid every other year. I agree don't ever trust a hydraulic jack when going under a car ALWAYS have a backup incase the jack suddenly falls, Yes this can happen when there is air in the system or an o-ring failure. Ususlly the hydraulic system will give you warning signs. like lost of fluid, jacking but, the push rod don't work right, or jacking something heavy and it bleeds down on you are all signs of potenial failure.

i had the same issue on my kawasaki engine in a 2003 JD 235 a couple of months ago. the engine had to be removed to replace the sump gasket, certainly something i am not capable of doing. the fix is not inexpensive but given the quality and condition of the machine, it was worth it (they don't put k7x transmissions in entry level GT's anymore). about $500 in the balto/wash area plus the ridiculous pick up and delivery fee dealerships are now charging.

Probably the same as you. But, why do you not believe the tire company ? They are in the tire business. The difference in tread wear will not affect the transmission. The tire company was too broad in their statment. Your Transfer case will be affected as it tries to equilize the different " bites " of warn tread and new tread. ( or traction ) in other words.

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