Ex trip bucket... bleeding hydraulic lines

Discussion in 'Shop Talk' started by Ross, Jun 20, 2004.

  1. Ross

    Ross Moderator Staff Member Supporter

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    Ok we changed the near useless trip bucket for a hydraulic cylinder on our Freeman 2000 loader mounted to a 72 David Brown 990 selectamatic on internal hydraulics through a Greisen spool. I know the bucket cyl has air in the lines is there an easy way to bleed it out?
     
  2. james dilley

    james dilley Well-Known Member Supporter

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    Is there a tank with a filter? if so you can try bleeding thru the tank with the cap off ,just run it slow when releaseing the pressure or itwill spray .The other method is to crack open the lines one by one and bleed the cylinders,this will bleed the cylinders but is a messy way to do it.
     

  3. Ducks limited

    Ducks limited Member

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    Two things come to mind. First make sure your resevoir is full or a little over so the pump won't cavitate. Then make sure the bucket cylinder is lower than the pump/ resevoir of the tractor. Cycle it all the way both ways several times and the air should come out. You may need to pull the pin on the cylinder so it has no load on it.
    Your bucket cylinder is 2-way I'm guessing. My trip bucket loader is only one-way. I would have to change over to 2-way hydraulics to use a bucket cylinder. LOL, Dave
     
  4. Ross

    Ross Moderator Staff Member Supporter

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    Getting the bucket lower than the pump resevoir (the tranny) might be tricky. Yes the fluid is up though. I'm using the internal pump which is located low in the rear housing for the PTO. The lift arms are single acting (and the best I've ever had that were) and the bucket cylinder is double acting through and open center double spool running off the single action remote on the selectamatic control. It dumps into the top of the tranny. I probably should have tried harder to plumb it through the Cessna remote but its done now and works fine except for the air problem. Maybe if I run it down hill and try cycling it?
     

  5. So anyhow, this is a double-acting curcuit all the way through? Not sure about running a double through a single, how you mean that.....

    Most hyd systems like this bleed air out just by using them a dozen times or so. Especially double acting. A little tough starting at first, but keep it working & it should bleed out.

    Are the original loader arms working, or did the hyd shut down completely? If nothing works at all, perhaps your pump lost prime, and you need to get the pump flowing again. Most have a bleeder screw, you can prime through that with a squirt gun, let the bubbles out.

    --->Paul
     
  6. Ross

    Ross Moderator Staff Member Supporter

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    The loader is controled with a Griesen spool. The DB selectamatic remote which is a single action (one way flow) feeds the loader spool which directs the flow which ever way its needed. One side of the bucket spool feeds the dump the other side the curl. There is another lever on the Griesen to supply the lift. When neither is pulled the oil just runs through back to the tranny. The bucket cylinder lines have air in them, you can tell by the jerky action and sudden drop when dumping a loaded bucket. The internal pump is self priming, and I did add extra oil to the tranny to supply the loader. Everything works just the bucket is not smooth.
     
  7. Usually, just given time it clears up, as long as your pump keeps pumping. The air will bleed back to the return over a few hour's use. Can be agrivating on a loader control tho! :)

    Using care not to pinch youself or drop a loader on you or inject oil under pressure (trying to cover the liability thing) you can unsrew a hose by the cylinder, work it so oil is in, air is out. Do the same with the other side of the cylinder - bleeding into a bucket. Can also bleed the hose itself - both sided - into the bucket. Helps a lot, but is very messy.

    If you have a couple hours of no-so-exacting loader work, I'd just use it & let it clear itself up.

    I had a line on the plow blow last fall, rather long, put a new one one & it was a lot of air. Took 3 rounds, pump hollered at me at first didn't want to raise at first. Worked fine after that.

    --->Paul