Proper Hydraulic Fluid to use?

Yeah, don't use the stop leak fluid.

Try to find a repair shop that does automotive hydraulic lift repairs.
They can take you jack and find a seal that works.

Farm equipment repair, ask around the local co-op

I wish I had one close by, I could get my powergear curbside rear jack repaired

Hydraulics are used in many industries. Search for shop that specializes in that equipment. You might need to remove/replace it yourself, or hire somebody else to do it.

Stop thinking of this as an RV item that needs repaired. The cylinder is no different that that is used on a backhoe, front end loader, dozers and such. Getting it repaired shouldn't be a problem. Just keep in mind that shop service might cost around $100 an hour so there is a point when replacement is a more economical option but you won't know unless you try.

When I had an internal leak by, jack would extend and retract but would not lift the coach, I open a Google Map of my area (southeaster Virginia) and search for "hydraulic cylinder repair". Returned a dozen of possible sources to investigate within a 45 minute drive.

I removed the jack, four bolts and two hydraulic lines, drove down to the closest shop. They said no problem, shop service is $X per hour and shouldn't be more than 2 hours with $X for material. A few days later they call as the jack was ready. Reinstalled and cycled the jacks for full retract to full extent a few times to bleed any air and all was good.

WHERE did you read not to use Dextron 3. Motorhome Hydraulic Jack/slide systems ALL use Dextron 3. From the Kwikee owners manual. Doug

1. Be sure the leveling jacks are in the retracted position. Remove the breather cap
on the reservoir and check the fluid level in the reservoir. The fluid level should be
approximately 1" below the top of the reservoir. This standard provides an adequate
amount of fluid for the levelers to operate efficiently. If the fluid is below this level, add a
sufficient amount to bring the level up to the operating standard. When filling the
reservoir, use transmission fluid only. We recommend Dextron III. Do not mix fluids.

NEVER USE ANY TYPE LEAK STOP IN A SLIDE OR JACK SYSTEM. IT WILL GUM UP THE VARIOUS SOLENOIDS AND VALVES. Doug

MrWizard wrote:
Farm equipment repair, ask around the local co-op

I wish I had one close by, I could get my powergear curbside rear jack repaired

LCI sells the rebuild kits for Powergear Jacks. Doug

"Motorhome Hydraulic Jack/slide systems ALL use Dextron 3"

Not ALL systems use what you mention. Some use a different hydraulic oil including mine. Besides, there is no such thing as "Dextron"; it is Dexron.

The Dexron fluid can be used but it will discolor anything it touches red. That is why some systems, including mine,use a colorless hydraulic fluid. Probably the same composition but who knows

Dexron ATF is used in a lot of consumer jack systems mostly because it's readily available. A close straight hydraulic oil equivalent is AW32. It can be used in most jacks, but never use it in an automatic transmission since it doesn't have the correct friction modifiers that the clutch bands need.

navigator2346 wrote:
"Motorhome Hydraulic Jack/slide systems ALL use Dextron 3"

Not ALL systems use what you mention. Some use a different hydraulic oil including mine. Besides, there is no such thing as "Dextron"; it is Dexron.

The Dexron fluid can be used but it will discolor anything it touches red. That is why some systems, including mine,use a colorless hydraulic fluid. Probably the same composition but who knows

Sorry about the t. Dexron has a red dye. HWH fluid is Dexron 3 without the red dye. State what system you have that does NOT use Dexron 3. System and what fluid is recommended. Doug