Greetings. I have a 1989 army surplus D7G. I can't get the ripper to move up or down. How the lines flex when the lever is moved. If you move it in the up direction the up pilot line has pressure same for the lower .when you try to move it however the ripper doesn't move but the pressure lines jerk. When i used a gauge to check pressures the needle jerks then back to 0 to fast for me see . The spool in the valve in back next to the ripper is fine. I can move it back and forth the springs on the top and bottom are good aswell. I am unsure where to go from here. Would appreciate any and all advice
Chris, I'm not familiar with that but, is there by any chance a safety lock pin somewhere in the ripper frame?
Has it moved before ,or like this as long as you have had it?
There us no pin keeping it from moving. Yes the ripper has worked before. The last time it was out on a job. They had issues with it before they completed the job. Then it sat at the shop for a while no one bothered to mention it had a problem till it was getting to be loaded up for another job
Trash in a pilot control, power down power up, keeps tension on all cylinders during process.
Ive taken it down and it was clean. Put new Orings in before putting it pack together. forgot to mention that in my original post.
Has anyone had the lines off to the ripper cylinders and by chance switched them so one cylinder is fighting the other.
Possibly seals blown on pistons on rams I had a crane that would not boom up but hoses would jump and that was the problem
Pressure relief stuck open?
What's the s/n of the Hydraulic Control?
None of the lines have been off
Im not sure. I would have to wait till Monday to get that info
Did you look at them to see if they are hooked up correctly anyway? Don't want to overlook something simple. Also, did one of the ripper lines get kinked or bent shutting off flow? Did a big rock flip up and crush one of the steel tubes?
Are you talking about the packing seals on the cylinders them selves?
Piston seals Or possible piston off a shaft Other cylinders are locked until they build enough pressure to off set Piston off or seals destroyed eliminates that.
Does the ripper have both lift and tilt cylinders..? If so are they all not working or just the lift cylinders.? Have you tried temporarily un-pinning the cylinder rods and see what happens when you operate the control.? Also try operating the ripper and hold the control lever in one position, up or down it makes no difference, for 2-3 minutes with the engine at high idle. Then go and (carefully) touch the cylinder barrels. Is one or both of them hot in approximately the location where the piston ought to be.?
It just have lift no tilt
Try the other two suggestions then.
If you find anything warm, you could disconnect the lines to that cylinder and cap them at the machine side, leave the cylinder hoses going into a bucket hopefully. It should lift with one good cylinder if the other one is disconnected so it can't bypass. Or, if you don't find anything warm, disconnect the common supply line to either the raise or lower, and put the pressure gauge there, to tell if the valve is supplying pressure, because you couldn't find any heat in the cylinders.
Well it turned out. They both rams had broken off. After i had unpined it. Forgot to give yall an update after i did it.
A bit strange to say the least. Any idea how that happened..? I know - Operator response: "It was fine the last time I used it"...........