# having trouble with controls for bucket truck



## Robert A.

:bang: I have a 1987 bucket truck (gmc) with high ranger model #6td-65pb1.upper boom controls will go down but not up. lower boom will go up but not down. swing left but not right. the trigger will only work hydraulics for about 3 seconds at a time. all controls work from dead man. can anybody point me in the right direction.:bang:


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## lawson's tree s

sounds like it might be a relief valve. does your boom have a button to bleed the boom located on the turn table? could be the suction line coming out of the hydraulic tank could be getting clogged. check your pump pressure .


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## Robert A.

I havn't seen one on turn table.all pressure is good. I did have a leak on swing controls repaired and blead line all was good till today. i blead all lines from bucket back to deadman controls work for a minute. back to one on each fuction.


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## lawson's tree s

sounds like their is still air in the lines somewhere id try to bleed them again.


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## CalTreeEquip

*Check your control head.*

It's the control lines, or more accurately the trigger control that is operated on air pressure. It might be leaking at the control head or a crack in the line (it's the thinest line in the bundle). Also there should be a pod at the base of the boom that this line plugs into. There is a air intake filter in there that clogs sometimes. Is a very low pressure sort of thing. The pod generates air pressure in the control head when you compress the trigger. With low or now pressure the low pressure control valves in the control head won't work or will work slowly. This is providing that you have a pistol grip control head.
I also could be cracked control lines at the boom elbow. Or maybe your control head valves are so worn that they are sucking air but then the control head would be visibly leaking a lot, I would think this would be a gradual degradation, valves working slower and slower until they stop working. The fact that you have full control at the dead-man indicates that it's not in the main hydraulic, high-pressure valves or lines.
Ya, check the pod, make sure it's pumping air, that's you're best and cheapest bet.


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## bushinspector

+1 On everything CalTreeEquip said.
I replaced the line all the way to the valve. Works good now.


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## CalTreeEquip

*yes!*

Chock one up for the MadMatt!

:hmm3grin2orange:


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