Slow moving FEL

[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: