Excavator Gear Pump Diagnosis And Repair, Yanmar VIO50.

Back in my younger happier days I had a shrimp boat with a 471 Detroit and a Twin Disc hydraulic reduction gear. Worked perfect in forward gear but had to be babied in reverse, or pressure would drop to zero. In the off season I pulled the gear and disassembled everything. Looked perfect in every way. I gave up and went to a factory authorized repair shop. I had minimal to no funds and told the mechanic my issue. He agreed to take a look at my pile of parts and also said it looked as good as new. He was holding one of the clutch drums and shaft in his hand and was spinning the drum on the shaft while talking. All of a sudden he said hey that's not right. The clutch drum was supposed to be a press fit on the shaft and it was the one that drove the oil pump. So when any extra strain was put on the reverse gear the shaft would quit turning and no oil pressure. He felt so happy to have figured it out he gave me a used drum and shaft assembly and sent me back to my boat. There are good people out there!

I live in England & have never used heavy machinery so I don’t know why I look forward to your videos so much but I do 👏👏👏🏴󠁧󠁢󠁥󠁮󠁧󠁿🏴󠁧󠁢󠁥󠁮󠁧󠁿🏴󠁧󠁢󠁥󠁮󠁧󠁿

It's still hard to believe that something that pumps oil can wear out.

I worked on hydraulics in the USAF for almost 16 years. Your videos make me remember why I went into computer and network repair after the military. Military hydralic fluid was red and would ruin a uniform in minutes if you had a leak run down your arm.....fun times. Great repair and I hope you get the tracking worked out.

Loving the excavator videos. I mean this in the best way but I hope your excavator keeps breaking down so we get to see more repair videos! Major thumbs up for being willing to tackle these repairs.

Regarding pumps. High pressure pumps, like the gear pump you have there or a piston pump, are what’s called positive displacement pumps. They essentially move cavities around, as you demonstrated. This means, that come hell or high water, that pump will move something, as long as it’s lubricated, and given enough input power and sealing forces, it’ll drive any pressure, because it will output a certain volume per revolution, no matter what. The part about restriction is just relative to flow. If you have a large enough pump, a 2 inch pipe is enough restriction to create a certain pressure. However, as pressure in a hydraulic system is similar to voltage, higher pressure is easier to handle than higher flows, so we usually aim for low flow high pressure. Usually there’s some component in a certain design that sets your maximum pressure, for example a certain seal that gets really pricey above a certain pressure because no one uses them except NASA. Then your working pressure for that system is essentially maybe 60% of that.

First off I love the fact that you have caps and pulls for all your hydraulic fittings. Second please keep doing these video's I really like your comments as your working on things. Your understanding of how things work is impressive.

5/19/23; ..(1/2) hydraulic pump trouble shoot, removal, excellent close up camera shots, clear 'show-&-tell' explanations, re-install (no leaks) & psi test/adjust up to 3500 psi...all like factory new! Excellent video Jon! Your mechanical, video & verbal articulation make your channel A+ ! Stay safe & carry on!👍👍👏👏🔧⚙️💪✅️😊

I use the vacuum trick when replacing valves on fuel oil tanks.

I watched your vid on the stihl weedwacker yesterday. Today i fixed a guys 12 volt positive displacement waterpump for his camper van. The limmit switch got stuck and did not cut out the pump if the pressure got too high and his pressure relief valve kept on opening. Opened the limmit switch and saw the small plastic button melted on the contact due to too high pressure that caused the pump to pull too much amps. I made a cad drawing of the little button, 3d printed a new one out of abs, replaced it. And it works like a charm. Adjusted the pump pressure to below 200kpa, wich is the pressure rating of the pressure relief valvle.

Hey great job both troubleshooting and replacing that gear pump! I'm not a farmer, nor any kind of hydraulics mechanic (know only what you've taught us in vids) but really enjoy watching all your videos. In my opinion you are definitely one of the best Youtubers out there, hands down! I think a lot of the reason I enjoy your videos so much is because I'm a lot like you in the jack-of-all-trades sense. I strongly believe that everyone should be as self-suficient as possible and that way too many people throw away thousands of dollars paying mechanics for things they could learn to do themselves. I know not everyone is mechanically inclined, but those who are can save a Ton of money not to mention peace of mind knowing exactly what was done and how. Another great video! 🎉

You’re definitely a jack of all trades and a master of many….I always enjoy your videos , keep them coming !!

Jon, Your videos are among the very best "weekend warrior" jack of all trades type on you tube. Thanks for taking the time to show us wanna bees a few new tricks. And more especially you share your mistakes and we all learn from them.

Concise, clear, entertaining, and well produced, as usual. Thanks. 👍💯

Seeing all of those internal parts brought back a flood of memories for me. I spent a summer in college working in the shipping department of a hydraulic pump factory and was always fascinated by what we were manufacturing.

You are a patient, patient man aside from the dishwasher 😊 Steve

Good to see the Yanmar's content generator is still in good shape! 😂

Thank you for taking the time to explain how and why the pump failed. This was a really interesting video.

Man, I love being off on Fridays! I get to watch so many of the channels I love right away.

That pump you mention around 29:30 is also known under the name "Gerotor pump". In case someone has difficulties looking up how it works. They're pretty fun, and also used in hydraulic steering systems, like in a tractor or for the articulated steering system in a wheel loader (directly connected to the steering wheel).