Hydraulic Jack Problem

[Mister B]

Last weekend when I went to jack up my truck with an old 2 1/4 Ton hydraulic floor jack that I have, it pumped and raised the jack up ok (not great) with no weight on it, but once the jack gets to a certain height (still with no weight on it), I could only pump the jack up when the handle was almost all the way down to the ground with maybe 2 to 3 inches of travel left on the handle. That last 2 to 3 inches of travel was the only point that it had any pressure to lift the jack and it barely lifted at all, at that point.

I thought that maybe it could be low on oil, so I wiped some grease off of the jack and looked around and found what i thought could be the oil plug for adding oil. There were 2 flat head screw in plugs on the rear of the jack behind the base of the handle. One small and one large. The small threaded plug on the right had a sticker beside it saying caution do not adjust valve (or something to that effect). So I started to unscrew the larger threaded plug on the left, and once I started to unscrew it, oil immediately started coming out from around the threads, so I screwed it back in. If this is the correct oil fill plug, I guess the oil must be full?

Here is a picture of a jack similar to mine that I found online that most closely resembles the location of the plugs on my jack. Just like mine, the one to the right of the gear is smaller and the one to the left of the gear is larger.

Can anyone verify for me that I found the correct oil fill hole on my jack?

If that is indeed the correct refill hole, my jack seems to be full unless I did something wrong. I had the jack in the down position when I started to unscrew that plug.

Any other ideas what the problem with my jack could be .

Any help would be appreciated. Thanks.

 

[lametec]

You're definitely low on fluid.

The fill port is covered by a rubber plug. You'll find it on the side of the cylinder that's facing UP (as you look down on the jack). There's no fill port on the back where you're looking.

Here's a site with loads more info: http://www.hyjacks.com/H7.HTM

 

[Mister B]

I'll have to wipe the jack down tonight and take a closer look for the rubber plug on the cylinder.

Thank you for the graphic and the link.

 

[Hiball]

I'll have to wipe the jack down tonight and take a closer look for the rubber plug on the cylinder.

Thank you for the graphic and the link.

That illustration is of a hein werner unit and the unit pictured is a overseas jack. The 2 holes on the back are not fill plugs 1 is the working valve and the other is the overload. The fill plug should be on the resevoir in front of the handle assembly and will either be a threaded plug or a more than likely a rubber plug. Your symptoms are screaming "Low on oil" so pull the plug and add a little bit, do not overfill, Check and repeat as neccesary. Next question where did the oil go? Have fun.

 

[Mister B]

Thanks Hiball.

I will check it tonight and gradually add some new fluid and see how it works.

As to where the oil went, I'm guessing it gradually leaked from a worn seal somewhere over the years. I've never worked on a jack before, so I would not even know where to begin to look to try and fix it, or if it is even worth fixing.

I just hope that by adding some fluid I can get it working temporarily for now. If I could fix it though, that would be great.

Thanks.

 

[Mister B]

Well, I went out into the garage tonight and found that rubber plug and added some hydraulic jack fluid to the floor jack and it now works fine.

Thanks again guys.