Machine starts easily and moves and stops as it should. At times the equipment does not function, at times it does. Sometimes when its cold it operates properly, other times when its cold it does not. Running the engine at high speed seems to allow fluid into the joystick controls, sometimes not. A few times it quit operating after continual use for several hours, only to work again after revving the engines. Any suggestions? Thanks
Good day Suggest you begin by checking the servo pressure hot& cold at low and high engine revolutions. Kind regards Uffex
First thing check the lock out switch for intermittent problems! Then do “the works”! Check and if need replace or clean: suction strainer in the tank, strainers at inlet of joysticks, return filters, case drain filter. That’s preliminary “proper preparation” procedure before moving on to more serious diagnostics, and eliminating chasing your own tail and loosing your mind!!! IMHO!!!
Oh! Almost forgot! Hydraulic fluid tank breather - got to have some pressure in the tank when machine gets oil to operating temperature of at least 50F
Hi The hydraulic interlock (servo) is in the left console, it's a micro switch and adjustable. After that I would check the servo 'in' pressure. That is on the small block right behind the cab on the counterweight (there is a pressure reducing valve, relief valve, a couple of solenoids, and a test fitting) one solenoid is the pilot pressure but dammed if i can remember it's position. If you need the specs I can dig thru my books and find them. Hope this helps.
Thank you all for so quick response. I am new at this machine but have factory manuals. Will begin to troubleshoot next week.
Today I started up this machine and it functioned as advertised. I let it run for about 45 min and still worked good. Let it set for 2 hours and still works good. Tomorrow we take it to a job and see what happens. thanks to you all.
I know its been awhile, but this machine functioned as normal for some time and now has started acting up again. Please let me know what I could check.
Sounds like it comes and goes, likely electrical.
Thanks for getting back to me. I could not begin to get the suctions strainers inside the hydraulic reservoir loose, must need something special to get them out, however, the outriggers work and if there was a suction problem I dont think they would work. I have new spin on filters of the correct side and new aw32 oil. And so I am thinking electrical also. I have a manual and wiring diagram, but not sure exactly were the servo is. There is a component directly behind the cab that has 3 coils on it like for solenoids, and 3 or 4 hydraulic lines and a inline filter. Several years ago there were some issues and I cleaned out that filter and all was good. The book says to test wire #57 for 24v and wire 0 should read to ground, however, there are no numbers on either wire from any of the 3 coils, AND no place to probe for voltage or continuity. Guess I should just skin back some protective coating ? or perhaps remove a coil and have someone watch it when I put the interlock into position. Any advise is welcomed for sure. Thanks.
You can back-probe the plugs or just un-plug and check. The outriggers are electric over hydraulic, that tells us that main pumps are likely ok. The problem is on the pilot (servo) side. The valve block you are talking about is the correct one. The filter is on the brake side of the system. I would start with fuses first, then close the door and listen carefully as you raise and lower the L/H armrest (should be able to hear the micro switch click, I have an advantage there, I can turn up my hearing aids LOL At the solenoid block, If that's a Case built machine, strip back some harness and you will see the numbers, if it a Badger, ??? Quick test is un-plug the solenoid (Weatherpac plug) with the key on, L/H arm rest in operating position, 1 pin will have +24V other will be ground. Raise the armrest, should have 0V. A quick reminder, there is an accumulator in that system. DO NOT remove any lines or valves until you have discharged that! And yes, I have seen quite a few apprentices come out spitting hydraulic oil, and a lot of ...."good gosh, my oh my" and other dirty words. In my experience, most likely the micro switch or wiring in the L/H arm rest, or the coil has failed. hope this helps
Thanks again. I did the switch test from the book. I get 24v as advertised on #57 wire but the switch does not always cluck and sometimes it does not break contact when the arm is raised. I will order a new one to be sure. Also, if I rev the engine to almost 100%, sometimes I can raise the boom just enough to move the machine. It takes a min or so, but it has happened a couple times, mostly it just sits there.
Great work on the switch, you don't have to buy the switch from Case, check at your local electronic shops. Now, are you getting 24V at the solenoid? Sounds almost like you have a failed solenoid valve. I have replaced those with "Sun hydraulics" valves. Anyways you are on the right track! Good luck. Stay safe
Thanks. Today I cracked open the line going from the solenoid valve to the joysticks, then I fired it up and dropped to left control momentarily. Oil was everywhere. I closed the line and messed with some sort of pressure relief or IDK on the side of it. No change. I can put a gage on the joystick to check pressure there. I will try to upload a photo.
That is the pressure reducing valve.
Correct, the book describes it as a pressure relief valve. The coils on the opposite side are for the pilot control. at least one of them is. Today I disconnected the coils from the harness to check voltage and ground of the harness at the connector, got good readings, noticed the connector was saturated with oil. I pushed the coil wires back into the harness and now I have function!. Next I will clean it all up good and ensure the connections are tight. Thanks again for all your wisdom in theses matters.
No Worries To quote Jimi Hendrix "Knowledge speaks, but wisdom listens" Glad I could help Stay Safe