Allied 2 ton floor jack bleeding?

[KarlJay]

I have what I think is a 2~3 ton, all steel floor jack from about 1987. I wanted to bleed it as it's really not going up high enough and it's slow.

It's the same as this one: https://www.garagejournal.com/forum/threads/overseas-jack-rebuild-help-tutorial.51105/

I don't want to rebuild it, I just want to bleed and top off, or change the oil so that it goes all the way up and isn't so damn slow.

I also have an old HF jack that I screwed up trying to bleed. Now it does nothing.

Here's the manual: https://media.hcrcnow.com/uploads/drawings/u.s.general91039floorjack1.5ton.pdf

Basically I opened the center one, thinking that was the air bleed. Now it's not doing anything. Maybe I let in too much air, but even with more air, it should still pump something. Item 33 in the blow up diagram.

 

[Hiball]

It’s a little late now, but bleeding isn’t done via any valve plugs, it’s a simple process of flushing air that’s in the valve system and allowing any build up of air to escape via the reservoir fill/plug on sealed units.

The first jack is 35+/- years old, the immediate problem is more than likely a weak pump seal that can’t overcome the vacuum created in the sealed unit. A quick test would be to pull the fill plug (on the reservoir) and operate the jack assuming the oil level is correct. With that said… it’s 35 years old, seal life expectancy is near the end and had a good run.

The second jack issue sounds like you ventured into the working valve, called the high pressure valve on the diagram. Did you lose any of the components? The actual fill/bleed on that unit is on the block versus the reservoir.