Slow moving FEL

[Gary Sweat]

I'll start this thread so I can continue troubleshooting the loader without confusing everyone in TRH's thread.

Quote:
Originally Posted by Gary Sweat View Post
OK, I went ahead and ran the tractor in the garage. (cough, cough). Here is what I timed:

1000 rpm - loader to full height = 14 seconds

2000 rpm - Loader to full height = 11 seconds

Cylinders are 1.75" at 19" stroke

So there is some increase in speed just not much IMO

I also checked the return line to the tank and there is no oil flowing with the joystick in center position. Quite messy when you move it thoe.


If your numbers are somehow accurate, they indicate a 0.85 gpm pump flow at 1000rpm, and 1.1 gpm at 2000rpm....
accordingly flow is by passing somewhere.....go and get the pump tested during pressure (flow meter at both 1000rpm and 2000rpm), so we can get that pump eliminated from trouble shooting...
AKKAMAAN is online now Report Post Reply With Quote

 

[Gary Sweat]

The times are correct as I ran it a couple of times at each rpm to make sure it was the same.

One thing I did get wrong was the stroke. The cylinders are 19" but they are extended about an inch when sitting on the ground, so it puts them at actually 18" travel for the timed test. I doubt that makes much difference.

Can a gear driven pump put out pressure but loose gpm? It doesn't seem to have any problems lifting loads on the loader or the 3pt.

 

[Gary Sweat]

I dug around in the manual some more and came across a table that lists this model pump as 3.17 gpm. Maybe I'm seeing wear on the pump and time to replace it. Then again, maybe not:confused2:

 

[wdchyd]

I'll start this thread so I can continue troubleshooting the loader without confusing everyone in TRH's thread


If your numbers are somehow accurate, they indicate a 0.85 gpm pump flow at 1000rpm, and 1.1 gpm at 2000rpm....
accordingly flow is by passing somewhere.....go and get the pump tested during pressure (flow meter at both 1000rpm and 2000rpm), so we can get that pump eliminated from trouble shooting...
AKKAMAAN is online now Report Post Reply With Quote

Great idea Gary....my head was spinning....:confused2:

Akkamaan makes alot of sense about testing that pump to evaluate it's efficiency and possibly rule it out.....that way you can work your way downstream if it's good......have it tested on the machine with everything together (don't take it off )....

 

[AKKAMAAN]

Perhaps you forgot to multiply by 2 ?
larry

My point here is that it only takes about 1 gpm to move your cylinder with that speed....and you pump should put out 4gpm at some high rpm's.....so where are the other 3 gpm's......by passing some where....so I suggest you start with eliminting the pump by performing a pump test....See wdchyd's video....

Input and output numbers in yellow...

at
https://spreadsheets.google.com/ccc?key=0AgccLk48zZpwdHE2bjBLekE5cTZWMV9GalcyS0RvZFE&hl=en

Please check so my math is ok!!:thumbsup:

 

[Gary Sweat]

Great idea Gary....my head was spinning....:confused2:

Akkamaan makes alot of sense about testing that pump to evaluate it's efficiency and possibly rule it out.....that way you can work your way downstream if it's good......have it tested on the machine with everything together (don't take it off )....

Mine to after a while:laughing:

So was the chart for one cylinder or two? If it's for one then doubling the flow would put it pretty close to the pump rating. I really hate to take the pump off and drive 75 miles to see if it is working properly but that may be the only way. Also, don't want to buy a $400.00 pump just find out I don't need one. Unless I can get a bigger one

 

[wdchyd]

I really hate to take the pump off and drive 75 miles to see if it is working properly but that may be the only way. Also, don't want to buy a $400.00 pump just find out I don't need one. Unless I can get a bigger one

No, don't take off the pump.....even with the proper test stand, nothing beats testing on the machine.....that way everything in the system is tested.....quicker, cheaper and tested right....It needs to be tested as a complete assembly for troubleshooting purposes.....

wdc

 

[AKKAMAAN]

Mine to after a while:laughing:

So was the chart for one cylinder or two? If it's for one then doubling the flow would put it pretty close to the pump rating. I really hate to take the pump off and drive 75 miles to see if it is working properly but that may be the only way. Also, don't want to buy a $400.00 pump just find out I don't need one. Unless I can get a bigger one

Good Point ...Of course my "brain" only put one cylinder in....LOL....so gpm's gotta be doubled....1.7 and 2.2 gpm....still missing about 50% of flow...

Even if pump is bad, I have a hard time to see pump only as a fault....there gotta be some thing more into it....but you never know till it's ruled out...

 

[Gary Sweat]

Good Point ...Of course my "brain" only put one cylinder in....LOL....so gpm's gotta be doubled....1.7 and 2.2 gpm....still missing about 50% of flow...

Even if pump is bad, I have a hard time to see pump only as a fault....there gotta be some thing more into it....but you never know till it's ruled out...

Did you catch the post about the 3.17 gpm for this model tractor? Looks like I'm loosing about 1 gpm somewhere. Can that come from loss in friction of the lines or size of the cylinder fittings? I don't know, that's why I'm asking

 

[AKKAMAAN]

Did you catch the post about the 3.17 gpm for this model tractor? Looks like I'm loosing about 1 gpm somewhere. Can that come from loss in friction of the lines or size of the cylinder fittings? I don't know, that's why I'm asking

Friction creates power loss when there is motion present. Se turning wheel and a brake system. No heat is created when brakes are applied and wheel is not turning.

If flow going into a hose is 10gpm, the same flow will come out in the other end, but at a lower pressure. Unless part of flow is diverted, by passed or lost by leakage. That's why I am always preaching that restriction do not reduce flow in a constant flow system, restriction will control pressure.

In a constant pressure system, with a variable flow pump, a restriction will control flow.

Friction do not take away, or reduce flow....friction makes loss of pressure when there is a flow....no flow=no friction....much flow=much friction.....
Actually it is not the flow it self that makes friction, it is the internal friction in the fluid, that "quadruples" when fluid VELOCITY increases....so viscosity is an important part of the friction equation...

There can be 100gpm of flow, with almost no relative losses in friction, because velocity is low (large diameter lines), and there can be a lot of relative losses from friction from 1gpm, if the lines are to small...

Friction start to be an issue when velocity makes fluid turbulent more than laminar...now it make more sense that there is no friction losses when there is no flow, because there is no turbulence in a stationary (no flow) fluid....

If your pump is "bad", flow is lost by internal leakage in the pump...pressure caused by friction or restriction can increase that loss of flow....

 

[Window Geek]

Folks,
Just another polite question:
The pump rating at 3.17 GPM is at what RPM? That could be at an engine speed to achieve 540 pto speed, or even top engine speed. Check the RPM rating for that output. You may find your missing gallon.

Also, any chance of power steering on this rig?

 

[AKKAMAAN]

Folks,
Just another polite question:
The pump rating at 3.17 GPM is at what RPM? That could be at 540 pto speed, or even top engine speed. Check the RPM rating for that output. You may find your missing gallon.

Good point....that could be the case if pump flow is rated for about 3000rpm, that would cover for the missing 1gpm, but I doubt manufactuer of tractor would post that pump rating if diesel engine is rated for less than 3000rpm.....

 

[Gary Sweat]

The manual calls out 2400 rpm for 3.17 gpm. Is it going to pick up that 1 gpm with another 400 rpm?

The tractor doesn't have power steering. Whatever loss it has is down to either the pump or the CV. I don't think it would be in the CV since it is new. More likely somewhere in the pump. There is no blockage in the suction line or strainer (I checked it again).

One other bit of information I just thought about, I did the time test with the engine and oil at about 50 degrees. Don't know if that can make a difference but it does not seem to be any different in speed when it has been run for over an hour or two.

 

[Jbrink64]

I saw you used 3/8" hoses through out. Just a thought, at 4gpm, the oil will be flowing at a velocity greater than 25 ft/second. I try to keep the oil at a velocity no greater than 15 ft/second. Not that it will double the speed, but, 1/2" hoses from the pump to CV, and from CV to tank and 3 pt will decrease the mentioned frictional loses.

 

[AKKAMAAN]

I saw you used 3/8" hoses through out. Just a thought, at 4gpm, the oil will be flowing at a velocity greater than 25 ft/second. I try to keep the oil at a velocity no greater than 15 ft/second. Not that it will double the speed, but, 1/2" hoses from the pump to CV, and from CV to tank and 3 pt will decrease the mentioned frictional loses.

Can you verify this in math please....

This how I make it....

3/8=0.375

cross section area for 3/8" hose =0.375^2*pi/4= 0.1104466 sqi

4gpm = 4*231 cui/min=924/60= 15.4 cui/sec

velocity=15.4/0.1104466=139.4 inch/sec=139.4/12=11.6 ft/sec


see
https://spreadsheets.google.com/ccc?key=0AgccLk48zZpwdHJSRm95bnFGZV95eDBMV05aSUZxTmc&hl=en

 

[Gary Sweat]

Can we try something that I can understand? You guys are way over my head with the math:confused2:

Based on the cylinders, pump and hoses in my system:

Cylinders 1.75", 18" stroke from ground level
Pump 3.17gpm @ 2400rpm
hoses 3/8"
Steel lines .401 ID (pressure, feed and return)

How long should it take to extend the cylinders with no load in the bucket under ideal conditions? From that, I can determine if the pump is coming close to it's operational capacity. I'm sure there are other factors that have to be taken into account but it will give me a reference point.

An estimated guess would work for me.

 

[Johnbro]

My fel got slow when my hyd pump went south. Replaced the pump and the problem went away. Wasn't cheap, though (this was on my L2250).

 

[AKKAMAAN]

Can we try something that I can understand? You guys are way over my head with the math:confused2:

Based on the cylinders, pump and hoses in my system:

Cylinders 1.75", 18" stroke from ground level
Pump 3.17gpm @ 2400rpm
hoses 3/8"
Steel lines .401 ID (pressure, feed and return)

How long should it take to extend the cylinders with no load in the bucket under ideal conditions? From that, I can determine if the pump is coming close to it's operational capacity. I'm sure there are other factors that have to be taken into account but it will give me a reference point.

An estimated guess would work for me.

A good pump at no load pressure should use 2x3.55=7.1 sec sec to extend both cylinders. probably about 8 sec's at max pressure (about 15% internal leakage in pump etc.)

 

[Gary Sweat]

A good pump at no load pressure should use 2x3.55=7.1 sec sec to extend both cylinders. probably about 8 sec's at max pressure (about 15% internal leakage in pump etc.)

Since mine is taking almost twice that time, I can pretty much assume the pump is due for replacement. Took a while but I think we have gotten it narrowed down to justify buying a new pump.

Now the question is, are there any Yanmar models that used a larger gpm pump that might fit mine. Even with a little adapting. Surely they all weren't the same gpm

 

[Gary Sweat]

Oh, and thanks to everyone who pitched in to help resolve the problem. :thumbsup: