Aux hydraulics not locking in

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Skidder

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Mar 9, 2006
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I am a new skidsteer user, a '91 Bobcat 7753 (not 753) 46hp Kubota. Love it, and love this forum! I bought a used Clark backhoe attachment for the quick-tach plate, bought needed adapters to connect Bobcat aux hyd. to the backhoe, all hook up fine. But I cannot seem to lock in the hyd. pressure to the attachment. What I mean is, when I press the white button on the upper right once, it activates the attachment pressure but only while then flipping either switch on the right turning lever (either the finger trigger switch OR the thumb flip switch). But I am told that if I press the white button up there twice, the "lock-in" light should illuminate, and I can then get out of the ROPS and into the backhoe seat and go to work using its own levers, and Bobcat hydraulics. Problem is, I only get one light lit there at the white button, regardless of how many times I press the thing, enabling hyd pressure to the attachment intermittently using those finger switches. The net result is, I cannot use the backhoe. I also try to press the white button twice, then flip the switches on the lever--no difference: lock-in light remains unlit. Can anyone suggest a solution? I need the backhoe in 36 hours to dig trenches for septic evaluation. HELP! Thanks!!! Kevin
 

Tazza

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Call your local bobcat dealer, talk to the service section, there may be a trick to getting it to lock in, if not they can help you find whats wrong. I haven't fiddled with any 753's so i can't tell you :/
 

skidsteer.ca

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Call your local bobcat dealer, talk to the service section, there may be a trick to getting it to lock in, if not they can help you find whats wrong. I haven't fiddled with any 753's so i can't tell you :/
Something is wrong with the momentary and hyd lock switch. 1 press for cylinders momentary flow and you use the thumb switch on rh steering lever, 2nd press both lights on and squeeze finger trigger once on rh steering lever. 3 press and both lighs go out, aux hyd system disabled. in a pinch you could tape the thumb switch down (on the rh side I think would be flow in the proper direction) and get the contiuous flow you need to run the hoe. But you need to get it fixed because there is no trick to this as far as I know. Ken
 

Skidder

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Mar 9, 2006
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Something is wrong with the momentary and hyd lock switch. 1 press for cylinders momentary flow and you use the thumb switch on rh steering lever, 2nd press both lights on and squeeze finger trigger once on rh steering lever. 3 press and both lighs go out, aux hyd system disabled. in a pinch you could tape the thumb switch down (on the rh side I think would be flow in the proper direction) and get the contiuous flow you need to run the hoe. But you need to get it fixed because there is no trick to this as far as I know. Ken
Thanks to both of you for the information. I called the Bobcat dealer here in central TX, and they said it could be computer, wires, or solenoid. I had my son take it there in while I was at work, and they have determined that the finger trigger on the RH lever is "going bad", preventing the lock-in of pressure to backhoe. I'll personally look at it tonight after work and post a reply that may help future readers who need similar help with aux. hydraulics issues.
 

bobbie-g

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Mar 15, 2004
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Thanks to both of you for the information. I called the Bobcat dealer here in central TX, and they said it could be computer, wires, or solenoid. I had my son take it there in while I was at work, and they have determined that the finger trigger on the RH lever is "going bad", preventing the lock-in of pressure to backhoe. I'll personally look at it tonight after work and post a reply that may help future readers who need similar help with aux. hydraulics issues.
Skidder, I have a 751 which works (as near as I can remember) exactly like Ken explained it. On the second press of the aux hyd button, two green lights come on. Then, a momentary pull on the right trigger will start the hyd flow to the aux lines on the lift arms. I can't remember if another pull on the trigger stops it, or if the aux hyd button has to be pushed a third time. My 751 has the BICS (Bobcat Interlock Control System) with the display panel with about 5 leds, located back to the right behind the operator seat. --- Now, how to trouble shoot: Just a few guesses. Since you note that the aux hyd button is having an effect, I would assume the switch itself is probably working OK. And on mine, I had a bad seat interlock at one time that would not let hyd flow to the main drive motors, but I really don't think this is your problem, since 1) the machine would not drive if this were the issue, and 2) the system is designed to put flow to the aux hyd output on the lift arms without someone in the seat, just so a backhoe could be run. I would make sure all the lights on your BICS panel (assuming you have such a thing) seem to be working correctly (obviously the bar and seat light won't be on if you're not seated with the lap bar down). The other simple thing to check is just to raise the cab and poke around gently at the wiring harness under the cab. My 751 connectors are very well made and seem really keep out the dirt and moisture, so that is not an obvious thing to check. --- Seems to me from what you described that this most likely is a wiring or control problem, and most likely has nothing to do with the hydraulic system itself (pump, motors, etc). Just my two cents worth. --- Bob
 

Skidder

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Mar 9, 2006
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Skidder, I have a 751 which works (as near as I can remember) exactly like Ken explained it. On the second press of the aux hyd button, two green lights come on. Then, a momentary pull on the right trigger will start the hyd flow to the aux lines on the lift arms. I can't remember if another pull on the trigger stops it, or if the aux hyd button has to be pushed a third time. My 751 has the BICS (Bobcat Interlock Control System) with the display panel with about 5 leds, located back to the right behind the operator seat. --- Now, how to trouble shoot: Just a few guesses. Since you note that the aux hyd button is having an effect, I would assume the switch itself is probably working OK. And on mine, I had a bad seat interlock at one time that would not let hyd flow to the main drive motors, but I really don't think this is your problem, since 1) the machine would not drive if this were the issue, and 2) the system is designed to put flow to the aux hyd output on the lift arms without someone in the seat, just so a backhoe could be run. I would make sure all the lights on your BICS panel (assuming you have such a thing) seem to be working correctly (obviously the bar and seat light won't be on if you're not seated with the lap bar down). The other simple thing to check is just to raise the cab and poke around gently at the wiring harness under the cab. My 751 connectors are very well made and seem really keep out the dirt and moisture, so that is not an obvious thing to check. --- Seems to me from what you described that this most likely is a wiring or control problem, and most likely has nothing to do with the hydraulic system itself (pump, motors, etc). Just my two cents worth. --- Bob
Thank you bobbie-g and all for the helpful comments. The Bobcat dealer had asked me on the phone about the BICS, but my 7753 does not have the BICS panel, so we ended up taking it in to the shop. They (Bobcat) quickly determined the problem to be that, though the 2nd green light is not illuminating at all, the aux hyd would still lock in if you hit the white button twice, followed by pulling the finger trigger more or less REAL HARD til you hear the aux hyd stay on. So, the net result is, we have aux hydraulics, we just have to use our ears to know it, and not our eyes. I can live with that for now.
 

skidsteer.ca

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Jan 20, 2006
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Thank you bobbie-g and all for the helpful comments. The Bobcat dealer had asked me on the phone about the BICS, but my 7753 does not have the BICS panel, so we ended up taking it in to the shop. They (Bobcat) quickly determined the problem to be that, though the 2nd green light is not illuminating at all, the aux hyd would still lock in if you hit the white button twice, followed by pulling the finger trigger more or less REAL HARD til you hear the aux hyd stay on. So, the net result is, we have aux hydraulics, we just have to use our ears to know it, and not our eyes. I can live with that for now.
Glad to here your're all set to dig. Ken
 
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