So I have a JD 310SG that has me lost. Been chasing the problem for awhile and cannot figure it out for the life of me. The problem is Ill run my boom up and whenever I run another function the boom just stops then as soon as i let got of that function the boom runs like normal. It also does this when i run the stick out. Ill run the stick out and as soon as i run another function it stops in its tracks and as soon as i stop running the function the stick will start moving again. It also has a little hickup in the bucket. if the bucket is curled out ill start curling it in and once it hits its middle point it has a brief stop then curls up slow. If I bottom out the out riggers and have them over relief then the bucket curls just fine also if I run the extendahoe over relief the bucket curls just fine. Anyone have any idea what is going on or what to test???
Welcome to HEF Brady ! Serial number? Is it pilot operated controls or wobble sticks? How long have you owned this machine. Are you trying to raise the boom with the lever all the way then activate another function all the way? Multifunctioning on those machines only works if you are "feathering" functions because the oil is going to take the path of least resistance. What are your cycle times. Boom raise from the ground with the arm all the way out and bucket dumped, engine at fast idle? Arm in and out times, and bucket curl/dump times?
Serial is to310sg941558 They are pilot operated Had it roughly 5 years. It does it when I am feathering the functions also. I will get some cycle times after work today a post them.
Maybe filter is plugged? Reservoir full of hyd oil?
Finally got around to getting some cycle times. I did them at 1000 RPMs and 2000 RPMs. Boom raise with Bucket dumped and stick out and extend all the way out. 1K RPM - 9.42 Seconds 2K RPM - 5.14 Seconds Bucket Curl In 1K RPM - 23.21 Seconds Stops for a split second at the fulcrum point 2K RPM - 5.47 Seconds Bucket Curl Out 1K RPM - 6.80 Seconds 2K RPM - 2.86 Seconds Stick In 1K RPM - 28.99 Seconds 1K RPM With Extenda Stick Held Over Relief - 8.79 Seconds 2K RPM - 5.40 Seconds starts to stop and go like its out of oil while operating at 2K on this function Stick Out 1K RPM - 6.32 Seconds 2K RPM - 2.86 Seconds Heres all my results I hope this can tell you something and I appreciate any help.
Sorry, I should have been more specific. What is the loader boom up cycle time with the engine at idle? Those numbers you posted should have been done at wide open throttle. Do you have gauges? I would also suggest checking the pilot pressure. There is a diagnostic quick connect on the pilot manifold. It is mounted at the right rear of the machine frame. It will have a little ball shaped accumulator on it and the diagnostic coupler on the bottom. Turn the key on engine off. Enable the backhoe hydraulics with the switch. Cycle the levers to release the pressure. Now you will be able to connect a gauge to it. That pressure is checked at Fast idle and holding the backhoe bucket stalled for 30 seconds. What is the pressure with the bucket stalled at fast idle? Spec is 625-675 psi. There should also be a diagnostic coupler mounted to the backhoe valve. That is for the system relief pressure. Standing in the rear looking at the valve it will be on the right side toward the bottom. That pressure should be checked at Wide Open Throttle as well with the bucket curl stalled. Spec is 3525-3725 psi.
Finally got around to redoing the tests and the pressure tests. Loader bucket up cycle time @ idle 8.49 seconds Boom up, arm out, bucket curled out @ WOT 4.1 seconds Arm in WOT 2.91 seconds Arm out WOT 4.02 seconds Bucket curl in WOT 2.72 seconds Bucket curl out WOT 2.19 seconds System relief pressure 3600 psi Pilot pressure Bounces between 380 and 440 psi
This tells me the hydraulic pump is most likely OK. If this was checked with the bucket stalled then it is way too low. Low pilot pressure can be the source of slow hydraulics.
Yes it was checked with bucket stalled. Is there anything I can do about slow hydraulics??
Refer back to my previous post.... when was the last time the filter was changed? Also, is the reservoir full of oil when you are using the machine?
First you need to adjust pilot pressure up to spec.
Got the pilot pressure adjusted and steady at 675 PSI. It improved the speed of operation a little but still operates slow. I also replaced the filter and cut the old one open and nothing obvious was in there. Any more ideas?? I also noticed another symptom that when i boom down fast the boom goes then stops then goes then stops then goes.
Does the unit steer OK? At this point a flow test of the hydraulic pump would be in order. Something I want you to try. With the seat facing forward but not quite locked into place (you out of the seat), engine at idle, raise the loader boom and while holding the lever full stroke and while the boom is raising spin the seat to the backhoe position while watching the loader boom. Does the boom pick up speed (it should be noticeable). I have been able to move the seat back and forth and watch the boom pick up speed and slow down. If it does not pick up in speed then there is an issue with the auxiliary pump turning on. As far as your B/H boom being jerky check the item in the picture below.