A few years ago, I bought a Craftsman 4 Ton Low Profile Service Jack at sears. It had a really beefy frame and looked like it was great quality. At the time, there weren't 93 reviews with 2/5 stars on average on the sears website.
http://www.craftsman.com/craftsman-4-ton-low-profile-high-lift-service-jack/p-00950168000P
First of all, I've read they sticky and many other threads about how to fill and bleed floor jacks. None of them seemed to address a "fast up" jack. I tried the bleeding procedure in the Operators Manual with no effect. There is a sticker on the jack that tells you a different way to bleed it than what the manual tells you (go figure).
I've been talking to some other engineers here at work and based on what I described to them, they told me to keep bleeding it (but I've tried this for hours... literally). I fill up the reservoir all the way and put the plug back in. When I try to bleed it right after filling, it blows oil out the plug when I push it open slightly with a screwdriver. Here is what I have been doing to bleed it:
1. Open release valve
2. Pump handle quickly several times.
3. Crack open the oil plug slightly to let air out. I always get a little air out on this step. Right after I fill it up (with the ram fully retracted), this step blows oil and air out of the fill plug.
4. Close release valve.
5. Pump handle until the lift arm reaches maximum extension and continue to pump several times with my foot on the saddle.
6. Open release valve and let saddle go to the floor.
Close release valve and check for proper pump action.
7. Crack open the oil plug slightly to let air out. (I always get a little air out on this step too.)
I do this ten times or so and check the jack to see if its working. It will still not lift a load. The fast up function works fine, but once it starts to lift the load, it pushes it up slightly(1/2" - 3/4") and then lets it right back down. I can sit there and pump it forever with the release valve closed and without raising the load up.
Any other suggestions or bleeding techniques I could try?
http://www.craftsman.com/craftsman-4-ton-low-profile-high-lift-service-jack/p-00950168000P
First of all, I've read they sticky and many other threads about how to fill and bleed floor jacks. None of them seemed to address a "fast up" jack. I tried the bleeding procedure in the Operators Manual with no effect. There is a sticker on the jack that tells you a different way to bleed it than what the manual tells you (go figure).
I've been talking to some other engineers here at work and based on what I described to them, they told me to keep bleeding it (but I've tried this for hours... literally). I fill up the reservoir all the way and put the plug back in. When I try to bleed it right after filling, it blows oil out the plug when I push it open slightly with a screwdriver. Here is what I have been doing to bleed it:
1. Open release valve
2. Pump handle quickly several times.
3. Crack open the oil plug slightly to let air out. I always get a little air out on this step. Right after I fill it up (with the ram fully retracted), this step blows oil and air out of the fill plug.
4. Close release valve.
5. Pump handle until the lift arm reaches maximum extension and continue to pump several times with my foot on the saddle.
6. Open release valve and let saddle go to the floor.
Close release valve and check for proper pump action.
7. Crack open the oil plug slightly to let air out. (I always get a little air out on this step too.)
I do this ten times or so and check the jack to see if its working. It will still not lift a load. The fast up function works fine, but once it starts to lift the load, it pushes it up slightly(1/2" - 3/4") and then lets it right back down. I can sit there and pump it forever with the release valve closed and without raising the load up.
Any other suggestions or bleeding techniques I could try?