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Re: hydraulic systems?
Re: hydraulic systems? -- dwaldron	Post Reply	Top of thread	Forum

Posted by: maytag ® 11/23/2004, 10:59:49 Author Profile Mail author Edit

What type machine are you operating??  Maytag

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Re: hydraulic systems?
Re: Re: hydraulic systems? -- maytag	Post Reply	Top of thread	Forum

Posted by: dwaldron ® 11/23/2004, 11:26:28 Author Profile Mail author Edit

The machine is a track/skidder I use in logging small diameter timber; brand name is Dalco, made in Wisconsin. It was originally manufactured with mechanical drive and I converted it to hydraulic drive. The system consists of one engine driven gear pump, one 2 spool flow/steering control valve, and two gear type hydraulic track motors.

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Re: hydraulic systems?
Re: Re: hydraulic systems? -- dwaldron	Post Reply	Top of thread	Forum

Posted by: maytag ® 11/23/2004, 12:27:18 Author Profile Mail author Edit

Most all mobile equip. that is hydraulic drive employs a "closed loop" configuration-pump and motor tied directly together with a charge pump feeding both as needed-with this setup run away does not happen.  from what you describe it sounds like you have an open loop system-pump flow being directed to the motors thru a directional valve of some sort.  The run away came be prevented with the use of a brake valve.  When you experience the run away the motors and possibly the pump are more than likely cavitating-not good for long life and reliability. You might check the tank for a return filter or strainer that has come apart-thats the only time I've ever seen hydraulic fluid come out the top unless it is overfilled.  Maytag

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