How much hydraulic fluid for a jack?

[DaktariEd]

OK, I'm getting ready to take the Phoenix (the Pinzguaer) out for an overnight camp and trail run next week, checking fluids and such.
Checking the jack, the towel I had wrapped around it is soaked with hydraulic fluid. This particular bottle jack is apparently German or Austrian, the partially remaining label is in German.
There is no plug on the side as my other bottle jack has. Instead there is a threaded plug in the top rim, that has a plunger in the center. When the entire plug is removed, the last few drops of oil drip out when tipped over.
There are no fill lines as far as I can tell on the jack body itself.
I added a few ounces of the last jack oil that I had.
But how full should I fill it???
Obviously, I don't know jack...

Ed

 

[madizell]

If I may suggest, try extending the jack with the oil you have. If it achieves full extension without cavitating, it is good to go. If it goes up only part way and runs out of juice, it literally does not have enough juice. Ultimately, you need sufficient oil in the reservoir to fully operate the jack, and a bit more.

Conversely, if you overfill the reservoir, it will tend to spill out or pump out oil on retraction because the oil will overfill the reservoir and have nowhere to go. This can happen if you fill the jack while it is partially extended. With the jack fully collapsed, I would fill it until it is full, and put in the plug, then see if it works.

 

[DaktariEd]

Thanks for the info. I was considering a 3/4 fill for similar reasoning...
Here are a couple of pics.
Have you ever seen a bottle jack with a curved rocker-bottom?

 

[Ron B]

I have a similar problem with my hummer and the way the jack goes into a hole in the bottom of the a-arm. I've wanted to have an attachment fabbed to fit on bottle jacks, so I can use anything I find -- you might want to do the same (you'll probably beat me to it as I've been wanting this forever and still haven't had it done!).

Post pics of your pinz in action -- I love those trucks!

rb

 

[madizell]

Thanks for the info. I was considering a 3/4 fill for similar reasoning...
Here are a couple of pics.
Have you ever seen a bottle jack with a curved rocker-bottom?

No, but I suppose it will not only work on most angled surfaces, but will also have a pretty good footprint in soft sand.

 

[Pad]

Land Rovers have those types of jacks (w/ curved top), since there are no flat spots on the bottom of the axles this helps keep it centered. Haven't tried one though, they stay in the 'paved road only' trucks. I prefer a floor jack for off road, along with a strip of 3/4 plywood (for soft ground) and a chunk of 4x4/6x6 for added lift.
Just be sure to test your jack out(under load) B4 you go out, injested air can be a real downer if you need the jack.

Happy Jacking? (doesn't sound right)

Pad

 

[DaktariEd]

Actually the curve I was talking about is the base itself.
It is like a rocker-bottom; the entire jack actually rocks back & forth a little.
Strange.

 

[Pad]

OH ya now I see! I bet its so the jack maintains a 90deg. angle with the axle.
Smart I always wondered how far you could jack before it begins to slide on the axle housing.
Thank goodness for Volvo engineers, actually field testing their stuff!

Tonight-I sleep well.
Pad