I have a gray market Yanmar Vio30-3, 2005 era. Bought it with some hydraulic leaks, fixed those no problem, topped off the hydraulic fluid, it was 5 gallons low. I knew it was going to need some TLC. In the video attached, once it is warmed up, maybe 5 min. There is a buzzing sound coming from the pump area. It gets worse when the handle is down activating the controls. Can't hear anything when the machine is cold. But once it warms up, it buzzes and the hydraulic power gets really weak, engine sounds fine. Is this a solenoid that is sticking? I have a strong suspicion that I need to replace all the swivel gaskets as I can't drive in a straight line and turning causes the blade to go up or down depending on how you're trying to move. So I think I have some "blow by" of hydraulic fluid in the swivel. But I cannot pinpoint this buzzing sound. I have already replaced the gear pump. Photo is of the machine with all the covers on, I have them all off as I troubleshoot as seen in the video, and the old gear pump. Only other thing I have done is remap the control lines to the pattern selector so that I can have backhoe controls, I switched from ISO. Appreciate any guidance. Link to YouTube video of the sound
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There is a link to a video at the end of the post. Here is again -
Just sounds like small amount of fluid flowing.
What would cause it to not flow? The hydraulic fluid is topped off. Could there be a stuck solenoid? The buzzing sound does increase in volume with more throttle and quiets down with less throttle. The video is of the machine at idle. One more thing to note is that the high speed travel pedal does not work. The button that the foot pedal pushes is rusted in the closed position, but I don't see that affecting this.
With the fact of functions doing other functions, I'd suspect swivel spool is bypassing. Buzzing to me just sounds like oil flowing, but cameras don't pick up sound well.
When guards are off, sound is amplified so a person can be fooled. Have to agree with IceHole that the swivel must need resealing as you have wonky functions. Simon C
I will definitely be doing the rebuild on the swivel as I know that needs addressing. I am not following though how any bypassing in the swivel would cause this noise when the machine is idling and not moving. When the machine is idling, and no input is being given, isn't the pump just dumping oil back into the hydraulic tank?
You could have an issue going on. Worth getting some other more experienced people thoughts. I have seen this units rarely. Simon C
Thanks Simon, I got it up on blocks today. Will try to tackle the swivel removal this week. Already secured the seal kit, so just nee to knock it out.
Well it took a long time to get this out of the machine. But I am hoping this was the cause of the buzzing. Out of I think 7 seals, only 2 were fully in tact. I would say 2 at 50% and the rest were basically gone. Will get this put back in over the next couple weeks and update then. I know the machine will run so much better, just curious now if the buzzing is from all the bypass or if there is some gasket stuck somewhere causing a block.
Nothing is going through the swivel when you just put the lever down like that. There are case drains from the drive motors but those are not a source of flow until you mash a travel pedal.
It looks like water got into your system during its life, judging from the rust stains on the core of the swivel joint.
Got the swivel put back in and no leaks. I moved around to get the air out of the system and it seems to function great. After a minute or two the buzzing started to come back. So knowing that there was lots of O-ring debris in the system and based on @SLK001 's comment about water and rust, I drained the hydraulic tank and removed the suction filter. Pretty sure I found the problem for the buzzing! Shoutout to @IceHole for his comment on it sounding like low fluid flow. I don't know how it functioned at all with it being as blocked as it was. I feel dumb for not considering this, but I do have a receipt for a work order from the previous owner where it says they "installed hydraulic pump and cleaned hydraulic tank". So I was thinking it was something else. They probably just drained it and relaced the main filter. Work order was dated 2022. Guess you can't trust other peoples work. So long story short, it did appear to be water at first when I drained the tank, I'd say maybe 6oz, then a bunch of snot and shmoo and finally semi decent looking oil. But I would say it looked hazy/milky and not clear. Once drained, I got the filter out. I scrubbed the bottom of the tank and got out so much crap. I poured in a couple quarts of fluid and tried sloshing around as much of the crud as I could and drained again. Got my arm up in there as far as I could. Not sure what else I can do other than fill it back up and let the filters do the work. I will replace both filters and run new fluid. Does it make any sense to buy 2 sets of each filter, run the first set for an hour or two and then drain and replace them to get as much crud out as possible? Appreciate all the comments and suggestions.
That's some serious stuff, what's the other filter look like? Joe H
Yes Yes Yes on another oil change in a short while. Pretty cheap fix. Then consider how the water got in there. Look at the tank filler and top of the tank, etc. Consider tarping the machine when not in use. Perhaps the machine went swimming? You might find other evidence of that.
@Joe H It didn't look too dirty. But it was damaged. Hard to see in this photo, but the inner side of the filter was bent in, allowing some fluid to squeeze by unfiltered. @skyking1 I will double check to see where any water got in. Fill cap was on real tight and the filter lid was screwed on good and O-ring looks good. When I got the machine, it was low on fluid, I put in about 5 gallons of fluid. I believe it had been sitting outside for a year because of a hydraulic leak. So I think that that might have allowed room for some condensation. I also live in the Pacific Northwest, so lots of rain and high humidity. But I will double check the top of the tank this week. I didn't see a vent on the top of the hydraulic tank, but I will l look closer. Are you saying to fill with new fluid now, then replace it all out again? Or just replace the filters?
yes a fill and dump. It will help scavenge out moisture that is out in all the lines and cylinders.
Meeeeehhh. Nasty. Definitely buy filters and consider at least 2 other oil changes and literally buy a case of filters. I would check the suction filter a few more times in between.
Is that mostly rust, or something else? I hope that it is something else. Run a magnet over the mess and see if you pick up any particles.