Problems with my Vario Excavator

[cbazq271]

Hi, I just have a question about the Vario excavators. I just bought one a day ago, its a 850d version. It was already built and it came with no instructions. I was running it this morning and it was running great. I was using it and the hydro pump was running nice, smooth and quite. One of my scoops of dirt was wet dirt and when I spun to dump the dirt the machine tipped forward onto its bucket, not much maybe picked the back of the machine up 3 inches. As soon as it did this the pump started to sqeel real loud. I turned the pump off a second or two after the pump started sqweeling. Now when I turn the pump it sqweels and the pressure gauge needle jumps all over the place. If I slow the pump way down the sqweeling stops and the gauge works fine. I think it has air in the system somewhere. What do you think? Also how do you bleed the air out. I think when I first got the machine the gauge had some hydro fluid in it, It looks like there is not any in it now. This would explain the bouncing needle, how do I get the air out. Any help would be great thanks, Chad

[pigeonfarmboy]

Crazy, how did you find one so fast? Should have mine by the end of the month!

[Espeefan]

The gauge most likely was a liquid filled gauge. They fill them with liquid to reduce the pulsatation effects of pumping and help dampen the needle movement under natural vibration and pressure spikes. This is probably why you see the needle jumping all over now. Sounds like the gauge leaked out it's liquid, which is not hyrdaulic oil, by the way, but usually a glycerine, silicone, or halocarbon fluid.

If things were running fine before you tipped the machine, then perhaps the tipping caused the pump to suck in some air, as the oil level might have sloshed forward or away from the pick-up. How does the model run now? Are the cylinders jumpy and jerky? That would be air in the system, which I would think should eventually bleed itself out, after a few cycles. Unless your pump is not self-priming, and I don't know if it is or not, it could still have air inside it, or the system, causing problems. In that case, maybe try priming the pump by filling it's case with oil, before starting it up again. Once it starts pumping oil, any air in the system should be worked out in a short order, as the cylinders and valves are cycled.

If you feel the need to bleed the air out faster, then you might have to loosen a cylinder hose fitting (on the cylinder that acts soft, jumpy, or jerky) a small amount, cycle the cylinder, and watch to see if any oil seeps out of the loose fitting. You can do cylinder both ports, but do one at a time, and do the end of the cylinder that is being pressurized. Tighten it back up, once you deadhead the piston, and before you switch directions to do the other port. It might get a little messy, so be ready with a rag to collect the oil.

This is usually what I do at work, if I have air in a hyrdaulic system, but the majority of the time, the air will work it's way out on it's own, when the oil returns to the tank.

[apfubar]

I read in one of the other forums of a user experiencing similar noises with his... Probably something simple. I think it was over at Scale 4x4.

Cheers,
AP

[cbazq271]

I tried a the suggestions and I think I got the air out, but the gauge is still not reading the right pressures. You can adjust the pressure limiter and the gauge does not change. I had the gauge showing 25 bars and it blew a hydro line just sitting there running. I am out of ideas. The gauge must be bad. One qustion for those that have a Vario, when you turn the screw one the prssure limiter clockwise, should the pressure go up or down?

[Lil Giants]

clockwise - higher press

Recommended pressure is 20bar.