Blackhawk SJ-3 Floor Jack Fill/Bleed

[Sunnyside]

After reading the "Show me your Floor Jack" thread, and reading Hiball's sticky on floor jacks, and after pouring over the repair parts manual I have for this model, and after looking online for an operators manual that actually defined which screw is which, and after reading a Hiball post where he says it is really common to pour jack oil down the wrong port, I thought I'd ask if anyone recognizes this jack and which slotted screw is the fill/bleed? The yellow tape is for reference. The repair parts lists these three screws as Power/Speed/Bypass circuits.
And NO, I did not butcher up the screws, but their abuse gives me hope that the former owner, being too stupid and lazy to get the right screwdriver out of the chest, probably also managed to open the 'jack in the box' port and eject springs and balls, who knows what was replaced...

My first goal here is to just fill and bleed the unit, and see what happens.

Thanks!

 

[Sunnyside]

Pics of the jack

 

[Sunnyside]

Last try on pics............

 

[Hiball]

Sj3 utilizes a cover plate over the reservoir, albeit somewhat covered up by the linkages, if you come straight back (up in the picture) from the valve you marked with yellow tape, step to left a inch based off the picture orientation, that should be the fill.

 

[Sunnyside]

Thanks Hiball- I'm sure I'll be in touch for the kit, but I'll try the obvious first.

I have been dying to ask you this question: Machinists and motor makers mark their oil fill holes, Ford and Chevy too. What started the jack builders on the path of being obscure about the simplest things? Pure secretiveness? Do they consider their circuitry proprietary?

 

[Hiball]

Thanks Hiball- I'm sure I'll be in touch for the kit, but I'll try the obvious first.

I have been dying to ask you this question: Machinists and motor makers mark their oil fill holes, Ford and Chevy too. What started the jack builders on the path of being obscure about the simplest things? Pure secretiveness? Do they consider their circuitry proprietary?

Its really not obscure, there are really only 2 types of reservoirs, the most common is the bottle that surrounds the cylinder, and yours that is on the backside. Once you identify what type you have it's pretty straightforward, on a side note, these manufacturers never intended on the consumer servicing there products, they all had "authorized" repair centers.

 

[Sunnyside]

Got it. Thanks.

 

[dewalt378g]

Sunnyside, Do you mind telling me diameter of your front wheels? I have the same jack and am looking for a set of those wheels. Thanks.

 

[Sunnyside]

I'll measure them tomorrow for you when I am burping this bad boy( it's at the shop). Since you are concerned about small issues like wheels, I assume that you actually have a working SJ-3? What did you have to do to get it right?

 

[dewalt378g]

You're correct. I didn't really have to do anything as it seems to work just fine (haven't really loaded it yet). I believe it just needs a little hydraulic oil. When pump it up it gets only so high then you hear that squishy fluid sound, also, it does this before engaging the limiter/release lever mechanism thingy. So yeah, the wheels are an "if I can find them" sort of thing. Everyone else that puts up pics has wheels like yours. Mine does not and it doesn't have the studs on the inside of the rails where the cover plate goes which makes me think it might be a later model. My SJ2 has those wheels, but I think they might be smaller. That's where you come in Oh and my screws are a little messed up too (also not my doing), so don't feel bad.

Do you have your cover plate? If you don't I'll post up pics of mine so you can fab one if you like.

 

[Sunnyside]

DeWalt- The wheels are 1 15 /16" wide x 3 13/16" in diameter. Or, 2x4. I have the cover plate, sad ugly thing it is, thanks for the offer.

In the SJ-3 mechanism, when you pump the pistons via the handle, what happens between the lever and the complete valve? Does the lever's pivot bolt, the one just atop the power screw, move in some way? After bleed/fill,and getting no ram action, as I watch the piston's action, I see co connection between the lever and the pressure inside the reservoir.

The other way of asking this might be, as the pistons work, how does the lever 'know' there is pressure in the reservoir? Via the complete valve, or the pivot bolt it rides on?

Thanks.

 

[dewalt378g]

Ok, not too sure exactly what you're asking, but I'll give it a stab. Hiball could give you a better answer, also, I haven't spent any time on the mechanics of the jack yet. I just got it a few weeks ago and thought it might be a good winter project, so it's somewhat on the back burner for now. But as to your question about the lever my guess is that it doesn't know that any pressure is there. It looks like a purely mechanical release/limiter (not to be confused with the release knob on the handle, but activates the same valve). When the lift arm raises it pulls that small rod (on the left in your pic) with it. When the nut on the end of the rod engages the lever it activates the release valve to keep you from over pumping extending the ram. Again, this is just my quick observation in the whopping 15 min I spent with the jack when I got home. I had some other pressing issues to attend to, so I just rolled it into the garage and went back to work.

As far as the pivot bolt I don't remember if it's just a fulcrum point or if it actually moves. If I remember correctly, I think this jack's default mode is that the release valve is always closed. Again Hiball would know right away. I'll take a look tomorrow and see what I can learn and let you know.

Thanks for those wheel specs. Now I have an idea of what was originally there.

 

[Frank1]

That look like the jack I just picked up a few days ago- creeping around looking for info on it ?