A couple of hydraulic line-related questions...

[Dougster]

The rental place I know best around here has CUTs and skidsteers. The skidsteer implements that use hydraulic motors usually require higher (10 GPM or more) flow rates that many skidsteers provide.

Yeah, and that's the problem. 97% of "QA" rental equipment available around here is really made for skidsteers. In many cases, they make you rent their skid-steer (or sometimes CUT) as well. I'll still check around, but I'd bet that simply buying a PTO-driven PHD from TSC is going to work out to be less costly.

Dougster

 

[MtnViewRanch]

Rent the equipment and you have the use of it. Buy the equipment and you have the use of it for a lifetime. If you need to rent more than 1 time, then buy it if you can. An old friend of mine told me a long time ago that it was ok to barrow or rent a tool once, but if you need it twice then you need the tool. That made sense to me and I have tried to stand by that when ever I could.

 

[Dougster]

Rent the equipment and you have the use of it. Buy the equipment and you have the use of it for a lifetime. If you need to rent more than 1 time, then buy it if you can. An old friend of mine told me a long time ago that it was ok to barrow or rent a tool once, but if you need it twice then you need the tool. That made sense to me and I have tried to stand by that when ever I could.

Suffice to say that you do not have a storage space problem and I do! As it currently stands, I cannot even walk around inside my over-sized garage... and as of next week, I've got to get a dump trailer in there too or risk losing my business license! I certainly agree with you on smaller tools, but in my case, occasional use tools that consume too much real estate must be evaluated differently.

Dougster

 

[SPYDERLK]

Dougster, good choice in increasing those continuous flow hoses to 1/2. As you know I had problems with the hydraulic delivery on my 7520. I have since found the air leaks in the suction side and now have loader times indicating 16.8GPM delivery at 1000PSI, but during my initial quest I instrumented my sysem with a permanent pressure gauge on the pump output. Now that I have rated 17gpm delivery this gauge reads 700PSI at PTO speed. That is 7 hydraulic HP! This means the engine is losing 8 or so HP to just pumping the fluid from and back to the reservoir at high revs. Mine has 1/2 hoses - most of the loss is the restriction in the valves the fluid must transit - but every bit of this wasted energy you can save will come right back to you as more usable ground and PTO power, and lower fuel consumption.
larry

 

[Dougster]

Dougster, good choice in increasing those continuous flow hoses to 1/2. As you know I had problems with the hydraulic delivery on my 7520. I have since found the air leaks in the suction side and now have loader times indicating 16.8GPM delivery at 1000PSI, but during my initial quest I instrumented my sysem with a permanent pressure gauge on the pump output. Now that I have rated 17gpm delivery this gauge reads 700PSI at PTO speed. That is 7 hydraulic HP! This means the engine is losing 8 or so HP to just pumping the fluid from and back to the reservoir at high revs. Mine has 1/2 hoses - most of the loss is the restriction in the valves the fluid must transit - but every bit of this wasted energy you can save will come right back to you as more usable ground and PTO power, and lower fuel consumption.
larry

Hi Larry - First off, congratulations on finding that elusive 17 GPM. It's amazing what a small air leak can do. Makes me want to double check my own suction line just for the added peace of mind.

As you point out, that pumping is not free even when it's not being utilized. The parasitic effect you note is certainly true, although the small gain I'll get from increasing the size of those two hoses is likely rather small in the big scheme of things. But I am a fluid systems design purist and it just seems wrong to me that the hydraulic supply lines to and from my 509 are all 1/2" except for those two short 3/8" sections of hose. It's just not logical and will contribute something to hydraulic oil heating during extended periods of use.

But the real underlying reason probably goes back to my long-standing desire to upgrade to a 511 backhoe someday for that extra couple feet of reach. It bothered me bad to find out that the 4110... which was originally expected to power a 511... fell short and was later limited to the 509 unless a PTO-driven pump was employed. Tractor frame strength & weight questions aside, I can't help but wonder if these reduced size lines contributed in some small way to that shortfall. Same issue with the use (on my particular tractor) of my "A" remote set instead of direct powering from the FEL control valve's power beyond connection via a hose swap as Bradco recommended at the time.

Related to this, I'm still researching the recent upgrade of the 4110 from 7.87 GPM to 9.5 GPM and if whatever was changed can be backfitted onto my machine. In my mind, the hydraulic system shortfalls relating to the 511's unacceptable performance cannot have been that great. I can't help but think these small changes... and possibly one or two others... might have made a difference.

Dougster

 

[SPYDERLK]

Dougster, you could, and any hydraulically equipped tractor could easily hydraulically power a 511 BH - - just not fast. Beyond that the trouble you would run into is heat due to the limited heat exchange area of a small hydraulic sump. Your hose change will help, but like you said the flow resistance is predominately in other circuit components. The 511 operates fine on mine at 1200-1400. I think you would get equal and acceptable speeds at less than full rated RPM. Heat would be the problem in your system even with a larger pump. I cant believe it would be critical tho.
larry

 

[Dougster]

Dougster, you could, and any hydraulically equipped tractor could easily hydraulically power a 511 BH - - just not fast. Beyond that the trouble you would run into is heat due to the limited heat exchange area of a small hydraulic sump. Your hose change will help, but like you said the flow resistance is predominately in other circuit components. The 511 operates fine on mine at 1200-1400. I think you would get equal and acceptable speeds at less than full rated RPM. Heat would be the problem in your system even with a larger pump. I cant believe it would be critical tho.
larry

Your logic would seem to be flawless... that the 511 should work fine, but just a bit more slowly. Still, I've gotten mucho advice that the 511 "may not function properly" on tractors rated near or below Bradco's specified 9 GPM minimum flow. At 7.87 GPM, you'd think the older 4110's would have been close enough... but apparently not! Hence my quest for 9.5 GPM!

I find it interesting that with virtually identical diameter hydraulic cylinders that the 509 is recommended for 8-12 GPM while the 511 is recommended for 9-12 GPM. There apparently must be something to that 1 GPM difference.

Perhaps I should be happy that my 509 operates so well at slightly below Bradco's specified 8 GPM minimum.

Dougster

 

[SPYDERLK]

Dougster Quote: "Still, I've gotten mucho advice that the 511 "may not function properly" on tractors rated near or below Bradco's specified 9 GPM minimum flow."

OK - darn it, Im going to see if mine doesnt function properly on my porta power hand pump! Wanna spell me at the handle?

Seriously tho, Im betting that if they even actually know something they are speaking to the capability to do simultaneous actions. That gets more and more difficult at the low flows. Still, these are possible with mine even at idle. Im guessing thats about 5GPM. You wouldnt want to work that slow tho. Mine is ok at what I figure is about 8gpm. I say go for it if you really want it. Do youthink your tractor will physically handle it??
larry

 

[Dougster]

OK - darn it, Im going to see if mine doesnt function properly on my porta power hand pump! Wanna spell me at the handle? Seriously tho, Im betting that if they even actually know something they are speaking to the capability to do simultaneous actions. That gets more and more difficult at the low flows. Still, these are possible with mine even at idle. Im guessing thats about 5GPM. You wouldnt want to work that slow tho. Mine is ok at what I figure is about 8gpm. I say go for it if you really want it. Do you think your tractor will physically handle it??
larry

Honestly, I just don't know the answer to your questions. I've heard both ways. I think a lot of it has to do with operator experience and how smooth & patient vs. aggressive he or she might be. Sometimes I think the 509 is too powerful for the 4110... let alone the forces that a 511 might put on it.

All I know is that the extra reach/digging depth... a mere 17 inches... in my humble opinion would be a plus worth paying for. Used 511's are out there for very reasonable money even if I would have to paint most of them red! I've even located a slightly used... near new... red one! I've already got the right subframe... and God only knows what I could get for my used 509 in trade or outright sale.

If I could only make it work without a PTO pump...

Dougster

 

[SPYDERLK]

Quote: "If I could only make it work without a PTO pump... "

If I had my BH on Ild go check its function @ 7GPM. Right now the back is busy in other ways tho. If the situation comes up I will and let you know.
larry