Tractor Hydraulics Performance Testing - Machine Underground -Tractor & Commercial Equipment Discussion Forum

Dougster · 08-29-2008, 01:37 PM

Just to start a new topic here so Kenny and Mighty don't get too bored...

... I need to do something to confirm and hopefully improve the performance of my KMW ML112 FEL and Bradco 509 backhoe on my Mahindra 4110. While I have no specific complaints, I've always felt these attachments should be able to do even better than they have done for me. Over the last couple years, I've investigated ways to improve (read: increase) performance but the measures suggested tended to be either very expensive or mechanically difficult-to-impossible... or both. I also tended in the past to focus more on adding features rather than addressing the issue of increased lifting or digging power. This past spring's purchase of the ULDM mini-ex only served to delay the need to address this TLB "power" issue... but the time has finally come to do it.

Various options under consideration include all sorts of re-plumbing and new plumbing possibilities, changing setpoints and changing out key components to the extent necessary.

Think of this as me trying to "overclock" my tractor's hydraulics!!!

But clearly, I need to start by documenting where I am right now. It's been suggested that if I am really low on performance (vs. manufacturer published specs), that it might just be due to filter pluggage or suction air inleakage or even valve/line pluggages... and those will certainly be the first things to check. Beyond that, I could have incorrect or drifted setpoints on the main relief and/or backhoe relief or leakage within the Prince FEL control valve. In regard to backhoe performance, I've been advised that utilizing a rear remote set for power is convenient but usually a very bad idea due to pressure drop and heat generated... but the other plumbing options have their problems and limitations as well. An independent PTO pump may ultimately be the best solution for the backhoe... but that also adds mucho switchover time to an already tedious task.

Many aspects of this have been covered before here and elsewhere. What I'd like to do here is start by asking how would you approach the task of verifying that FEL and backhoe digging/lifting performance is meeting the manufacturer's published specs. And let me be clear: this is not so much about system flow (gpm - which I have already verified)... this is really about static and dynamic system operating pressures (psig).

I have already started to buy testing components (gauges and fittings, etc.) and have my own ideas on how to proceed, but I would love to hear about member experience and your thoughts on how to proceed and what to expect. I know the b***h of this exercise is going to be in the small details... but I'd love to get started with a good sense of what others have done before me, if anything, in this regard.

Thanks!!!

Dougster™

**Ducati996** · 08-29-2008, 02:01 PM

measuring the PSI with a guage is the first thing to do, from the power beyond ports and the SCV valves. That should tell you where you stand within spec and take it from there I suppose.

Mickey · 08-29-2008, 02:14 PM

This is out of my comfort zone but that's not going to stop me.

You said you measured the system flow and since you didn't say anything about it, I'm assuming it is meeting specs. Are the tractor hyd spec's up to the recommendations of your backhoe? While the hyd specs may be met, do you feel/know if the plumbing offers any restrictions to the pumps capabilities?

I'd be a little gun shy trying to jack up the pressure above the factory spec as that would eat into safety margins on all the hyd components.

Keep us informed as to what you find out.

**PaulChristenson** · 08-29-2008, 02:20 PM

The price of a complete and proper set of hydraulic testing equipment is NOT a cost justifed operation for the average individual...

Plus an accident with hydraulics can be very dagerous...

**Kennyd** · 08-29-2008, 04:15 PM

The very first thing to do, and the cheapest as well is to test the pressure settings of the relief valves.
A gauge like THIS, a short piece of hose (optional) and a QD nipple that fits one of your couplers is all it takes. You may also opt to "T" a gauge, on one of your circuits (lift, curl, ect.) so you can moniter pressures real-time.

Dougster · 08-29-2008, 05:58 PM

Quote:

Originally Posted by Kennyd

The very first thing to do, and the cheapest as well is to test the pressure settings of the relief valves.
A gauge like THIS, a short piece of hose (optional) and a QD nipple that fits one of your couplers is all it takes. You may also opt to "T" a gauge, on one of your circuits (lift, curl, ect.) so you can monitor pressures real-time.

This is pretty much what I've assembled (equipment-wise) to get started Kenny... female coupler on one end, male on the other and I tee off to a 3,000 lb pressure gauge. This will enable me to check pressures on either FEL circuit (boom and bucket tilt) and the main backhoe feed (i.e., rear remote sets).

I guess I've been wondering about the correct protocol in order to get a number directly comparable to the manufacturer's published specifications. Obviously, I should set the engine at the right RPM (even though it shouldn't matter for relief settings) and top out and/or bottom out the particular circuit. Guess I also need to pay attention to hydraulic oil temperature as well for maximum accuracy. For the backhoe, I should probably try all functions/valves/cylinders to make sure the relief setting is not affected by any valve or cylinder leakage. This assumes, of course, that I can even reach the relief setting of the backhoe in the first place. If I can't, I am already in big trouble!

But these would all be what I would consider "static" pressure measurements... i.e., relief settings only. Don't I need to take "dynamic" measurements to gauge real time pressure drop effects through the various components and lines? Specifically, pressure drop through the rear remote set valves and through the FEL control valve to power beyond? Won't this be the guidance that will help me decide whether or not to re-plumb the red beast and/or upgrade components?

Later I want to talk about approaches for increasing operating pressures regardless of what I find out in this testing. Maybe just a little or maybe a lot depending on what shakes out.

Dougster™

**Kennyd** · 08-29-2008, 09:51 PM

Quote:

Originally Posted by Dougster

This is pretty much what I've assembled (equipment-wise) to get started Kenny... female coupler on one end, male on the other and I tee off to a 3,000 lb pressure gauge. This will enable me to check pressures on either FEL circuit (boom and bucket tilt) and the main backhoe feed (i.e., rear remote sets).

I guess I've been wondering about the correct protocol in order to get a number directly comparable to the manufacturer's published specifications. Obviously, I should set the engine at the right RPM (even though it shouldn't matter for relief settings) and top out and/or bottom out the particular circuit. Guess I also need to pay attention to hydraulic oil temperature as well for maximum accuracy. For the backhoe, I should probably try all functions/valves/cylinders to make sure the relief setting is not affected by any valve or cylinder leakage. This assumes, of course, that I can even reach the relief setting of the backhoe in the first place. If I can't, I am already in big trouble!

But these would all be what I would consider "static" pressure measurements... i.e., relief settings only. Don't I need to take "dynamic" measurements to gauge real time pressure drop effects through the various components and lines? Specifically, pressure drop through the rear remote set valves and through the FEL control valve to power beyond? Won't this be the guidance that will help me decide whether or not to re-plumb the red beast and/or upgrade components?

Later I want to talk about approaches for increasing operating pressures regardless of what I find out in this testing. Maybe just a little or maybe a lot depending on what shakes out.

Dougster™

Jeez Doug-you are DEEP! You need to get some full time work to get your mind off things like this!

-According to my JD Tech manual, it states to check the pressure at "normal operating temperature"
-As far as the rear remote/powerbeyond debate for the backhoe, I am definitely on the PB side of the argument. I do believe you will get better flow through the larger hoses/QD's of the PB loop that you will through most rear remote setup's...but unfortunately a flow meter cost's big bucks so it's not easy for us to prove...
-As far as static vs. dynamic, I think you will drive yourself to the poorhouse (or poorerhouse in your case) and the nuthouse (or nutier house in your case) trying to measure differences here...Best bet for the money IMHO is to get some pressure readings and let's see where you are at know.

**irwin** · 08-29-2008, 10:31 PM

Don't you love it when you have a great question and a good idea, only to be told how silly you are

.... But hey, inquiring minds want to know!

So.... would it be cheaper to replumb or cost effective to buy the equipment necessary to find out if you should?

Quote:

The price of a complete and proper set of hydraulic testing equipment is NOT a cost justifed operation for the average individual...

Plus an accident with hydraulics can be very dagerous...

huh! I guess not (hiya Paul) and it's dangerous..not that that's stopped you before.

BTW are there any screens in the Mahindra's hydraulic system you've overlooked or haven't checked for crud build up?

FWIW, I'd be interested to hear what anyone did to safely tweak the pressures in a system, or is it just changing out the hoses with the next size up and adjusting the relief valve? Would this do anything to increase lift or breakout abilities?

**PaulChristenson** · 08-29-2008, 11:24 PM

And when your pressures exceed Mahindra standards...

Dougster · 08-30-2008, 09:52 AM

Quote:

Originally Posted by Kennyd

Jeez Doug-you are DEEP! You need to get some full time work to get your mind off things like this!

This is the disease of a person to whom performance testing was a professional career and something upon which hundreds of millions of dollars changed hands. Yes, I still take it far too seriously.

Quote:

Originally Posted by Kennyd

-According to my JD Tech manual, it states to check the pressure at "normal operating temperature"
-As far as the rear remote/powerbeyond debate for the backhoe, I am definitely on the PB side of the argument. I do believe you will get better flow through the larger hoses/QD's of the PB loop that you will through most rear remote setup's...but unfortunately a flow meter cost's big bucks so it's not easy for us to prove...
-As far as static vs. dynamic, I think you will drive yourself to the poorhouse (or poorerhouse in your case) and the nuthouse (or nutier house in your case) trying to measure differences here...Best bet for the money IMHO is to get some pressure readings and let's see where you are at know.

Oh, I certainly agree with your last statement. First things first! I've got to start by getting some good general sense of how I am doing relative to published specs. But then the real fun has got to start if I am going to "optimize" (and hopefully even "overclock") this old Red Beast!