Hello to all. When operating machine all hydraulic function will stop. Front end back end and power steering. If you mess with the levers for a minute it will all start working again with normal pressure and speed. It started doing it about once a month and now does it a couple times a day. Sounds possible to be the same problem catman 3208 is having. I bought the machine new and has only 2000 hrs. Any ideas before I take it to the dealer. Thanks in advance.
I'd hook up a test light into the destroke solenoid connector with everything still hooked up, if you get power when it's running but not working then there's your problem. Not likely but easy. Otherwise, just the standard stuff to check, drive coupling, suction air leak etc, but no idea why that would be intermittent?
You should have a small filter at the top of your hydraulic tank. Remove it and try to blow through it with your mouth. If its plugged, I'm thinking it may prevent oil flow to your pump.
Thanks for the replies. I will try these things on monday. It has been doing this for a couple years, but has been progressively getting worse to the point where something has to be done. The machine has been maticuously maintained and sat in a heated garage all its life. I hope the lack of hours it isn't adding to the problem.
JS750, The filter I'm refering to is just an air filter that lets air in and out of the hydraulic tank. I'm thinking Delmer is closer to your solution than I, but its easy to do and should be checked from time to time anyway. If your pump is starved of oil due to an air leak in your suction line or not enough air entering your tank than you should hear the pump making cavitation noises and/or jerky hydraulic functions. So if no noises or jerky function then the destroke solenoid sounds closer to your solution.
Check the steering priority valve
Everything I say is based on a 610c so I may be barking up the wrong tree. How would you check the priority valve? Mine is supposed to prioritize steering (and everything else) over loader functions, so it cuts off only the loader if the pressure drops. There's also a pressure relief valve in there that could pop open and stick? ( that would cause some load on the engine and heat up the valve) When I've had hydraulic pumps suck air, it's always been when the machine is first started and the oil is cold. Where is the charge pump on this machine? is it part of the hydraulic pump or on the engine? if the charge pressure stops working for a bit, that could cause your problem. Is there any rhyme or reason to when it acts up? is it when it's working hard for a while, when it's just started, or just random? There's a cooler relief valve that bypasses the hydraulic oil cooler when the oil is cold and cause too much back pressure, if that stuck open it might affect the charge pressure, I can't figure out if it would or not, so that's a wild guess. Instead of messing with a test light to the destroke solenoid like I suggested above, just start the machine then go disconnect the plug and run it until you need to start it again.
This machine has a open center hydraulic system where the 610c has a closed center system.Check the coupler to the hydraulic pump at the vibration damper at the front of the engine.It has a gear pump and if that is sacked it will leak at the input shaft.l
OOPS! kindly disregard my previous comments. Hopefully the original poster will see this before he tries to find the destroke solenoid! I'm still interested to hear what the cause is.
Thank's guys. I'am aware everything 410 and bigger has a piston pump as opposed to the gear set up on the 310. After running an excavator the last 15yrs I prefer the piston pumps(wish I would've bought a 410) The coupler is fine and there are no leaks at the input shaft. The filters are all good and I don't think it is sucking air. It could act up 2min after initial start up in the morning or 10 hrs into a hot day. It's like you turned a switch off then back on. The only thing modified is the pump pressure. The dealer turned it up when it was just out of warranty. I was having a hard time craning catch basins.
Just changed all filters and double checked everything else. Is the priority valve sandwiched to the top of the loader control Val e? If so how do you check it? Can it be rebuilt on the machine or does it have to come off.
Priority valve on my 1992 310D is way up high between the front window and the hood right between the loader pins. Don't know how to test it.
Thanks Deon. I believe on mine being newer the valve is on top of the loader control valve. Trying to figure out if I should slide the valve out and see if the o-rings are ok.
I did need to remove the loader control valve and replace all of the seals and o-rings. I found about 3 o-rings completely chewed up and some others showing damage. I know your hoe is newer but still old enough to have damaged o-rings. My valve was quite easy to repack. Sometimes its best to get the o-rings from the dealer to be sure you have the right material/durometer for the application. Hope you find your problem.