Jack Oil Substitution

I have always used regular automatic transmission fluid or power steering fluid in my bottle jacks.

will tranny fluid ruin the hydro seals?

I have old bottle jacks that have had transmission fluid in them for c lose to 20 years now so I don't think it has any seal compatibility problems.

What can I add to stop the seals from leaking, since that is the cause for the need to add fluid?

New jack.

You can try the automotive stop-leak treatments for power steering pumps or automatic transmissions. They cause the seals to swell but they also can weaken the elastomers and cause them to breakdown. Best solution is to take the jacki apart and replace the seals or just go to Harbor Freight and buy some new jacks.

Jacks come apart real easy,

All of mine have had the seals replaced. Round and/or square section o'rings. Mind you, they're all of Japanese or Chinese make and use gear oil as working fluid.

Most have had rusty pistons because the kids will leave 'em out and they invariably get wet.

I see no reason why you can't use a medium weight engine oil.

Cheers,

Stu

Do not use brake fluid.It is not really an oil, it is more closely related to anti freeze than oil.It will destroy the seals.

Hi Guest,

Mineral oil has many names and hydraulic oil is one of them. See here. Veterinary mineral oil is relatively cheap (<$20 for 5 gallons). You can find it at farm and ranch supply stores. Home Depot has 1 gal. Hydraulic oil for $11.00.

-S

Mass marketing has driven the price of motor oils and transmission fluid very low. As stated before ATF is just fine for use in jacks. 20, or 30 weight motor oil will leak slower. What is the design and capacity of the jack. Harbor freight is hard to beat for tools that do not need to work hard every day. I know of a roofer that buys circular saws by the case from them. Cheaper than buying good saw blades. Good luck.

Thanks to everyone for all your response, they helped me out alot. after reading all your responses I change the fluid in the jack and replaced it with power steering fluid/w sealer additive. it worked great so far. but i found the real problem wasn't the seals at all it was a bad o-ring on the filler plug. now i just hope the new o-ring works and don't fail and drop the car on top of me. lol