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Inconsistant hydraulic pressure on 1994 Lull 644 Highlander II

gilmoreinc ยท 2012-09-17 11:59

I have 1994 Lull 644 Highlander II lift that is slow to respond due to inconsistant hydraulic pressure. I have been trying to find a service manual with plumbing diagrams but have had no success. Any suggestions?

Replies4
  1. #1icestationzebra2012-09-17 18:36

    When you say inconsistent, do you mean day-to-day or second-to-second? ISZ

  2. #2gilmoreinc2012-09-18 11:32

    1994 Lull I mean second to second. It surges.

  3. #3barklee2012-09-18 20:13

    Go to jlg.com. They have the service manuals for nearly all their machines. I believe you click on the services tab and then manuals.

  4. #4willie592012-09-18 22:10

    Lull made so many arrangements to their machines it will be difficult for us to troubleshoot. Some had linkage controls to main control valve, others used pilot operated joystick valves. And if I interpret "surge" correctly, I assume the boom functions have a surge in operation, not smooth. Do steering and brakes work proper, or do they surge as well?