Today a neighbour down the road came over and asked me if i had a couple extra hours to use his CAT 416 rubber tired backhoe. And help him excavate an area, and install a short water line. And a 8" sewer line. While working I noticed that while trying to multi-task with the machine. I had to let off one of the levers to do another.So if i was trying to boom down-stick in- and bucket level i had to let off a little bit to do this. I know i am a new operator ( and looking for work hire me! ) Read my thread in personnel! But every wobble stick machine i have used i have had to do this in. Why is this? Why don't i get that feeling while using a 420? I had to jump at this oppurunity even on a sunday! -Michael- BTW I looked back into a blackbooklog of my operating hours today. backhoe/excavator 516 hours. Bulldozer 564 hours 20/40 ton mobile crane. 311 hours. Roller ( lol ) 212 hours. Chinese BackHoe ( Shovel ) 414 hours. That's actual seat time. Machines moving. Not bad for being 18 i dont guess. That's with heavy equipment school, civilian contractors, army etc.
My 580E is the same way. I just thought that my pump was shot. Anybody know what you should expect as I've never run any other tlb,s?
It's called blending functions and in a modern hoe/excavator,you are supposed to be able to do this.There is either a bad valve or pump,maybe both--it needs to be checked out by a tech.
What series was the 416? Multi-functioning valves really came into force in the 1990s, so it's possible that an older 416 will have to slow one function to engage another (same with early 300-series excavators).
Idk what model but it was about a 2003 year machine with only about 1400 hours on it. -Michael- On brand new machines with RPM's at about 2000 while digging. In my heavy equipment school this happened to me.
A hydraulic pump puts out a constant flow of oil regulated by engine rpm. Increased rpm means greater flow until you've met the pump's full capacity. When you are performing one function, all the flow is directed to that chore. If you try to do more than one function simultaneously, the flow is divided between these functions and each one receives a lesser flow of oil. It's similar to having someone flush a toilet while you are in the shower, the pressure is reduced. Hmmmmmmm......I seem to remember someone saying somewhere that a good operator didn't need to know the mechanics of a machine....:beatsme The newer machines are supposed to have some kind of system in place to compensate for this. I've never operated one and haven't seen a break down of components to describe how it works.
Thank you!
There's a bit more related discussion here: just try and avoid the hijackery by some unscrupolous members and a bit more here:
I believe that new of machine should have a piston pump that is variable flow. Even so you only have so much flow to use and so much horsepower to move that oil. I don't recall if those systems were open center or closed center control valves. I can't think of any loader backhoes that have pressure and flow compensation. John Deere years ago used a closed center hydraulic valve and their own piston pump which made them pretty smooth to operate. However they still would operate the circuits at the lowest pressure first. Excavators are designed from the bottom up to run mulitple functions and most now include the full range of technologies that achieve it. Loader backhoes are compromise machines that have to cost within a specified range in order to sell in a very competitive market. Install the latest technology in a loader backhoe and you will find that the cost is equal to or greater than the excavator of comparable size. In my part of the country mini excavators are replacing many loader backhoes.