jd 4020 FEL issue

grayson20

Member
alright something doesn't seem quite right here...the other day i went and got a flat "pallet" of rock on the back of my pickup for a fireplace. the pallet weighed approximately 1700lbs. I have a 67 jd 4020 diesel with a allied 695 front end loader on it. the loader does have a grapple which weighs almost 800lbs in its self. I thought that loader should have no problems lifting that pallet off the back of the truck. I did not have my bale spikes on so i just looped a chain over my bucket and made a basket loop on the pallet. I was able to lift the pallet about 2ft then my loader stalled out and wouldn't do anything....i was able to use my bucket tilt and lift it on up another six inches just fine to clear the bed of my truck but my lift cylinders wouldn't go another inch. is that the sign of weak hydro pump? i also had a 3 point post hole digger on that has a down pressure cylinder and it it was plugged in but it was raised up. The loader should lift twice that no problem? Any thoughts? i know I'm rambling
 

no I have power tapped in below the brake pedal and return down by the filters.

the psi adjustment on the joystick could probably be turned up quite a bit...would that make a difference?
 
The leverage (mechanical advantage) of the lift cylinders changes over the arc of the loader boom. The leverage is usually the greatest when the bucket is at ground ground level, that is also where the "breakaway force" is rated. If you were had the loader raised high the lifting capacity is probably lower. Check your loader's operators manual for it's lifting capacity at different positions. I suspect your hydraulic pressure is fine. A shorter lifting harness might have given the loader cylinders better leverage.
 
(quoted from post at 16:59:39 02/12/18)
no I have power tapped in below the brake pedal and return down by the filters.

the psi adjustment on the joystick could probably be turned up quite a bit...would that make a difference?

FEL control valve relief valve needs to be totally closed as it's not normally needed on CC hyd system for loader
 
Is it a syncro or powershift? If syncro
charge pump will not run with clutch
disengaged. May have run out of oil to main
pump.
 
Check the stand by pressure on the tractor. It should be 2250 PSI but I rarely see them there. They slowly drift down over time. IF the tractor is at 2250 PSI then it is the control valve. It could be an internal leak but the loader would settle quickly if the cylinders where leaking.
 

1700lbs is not much rock by volume, that would be less than half a yard of concrete. Are you sure it was only 1700lb?
 
Is this the manual for your loader?

www.farm-king.com/downloads/manuals/Allied-FEL/loader-695-2006.pdf

The specifications on the fourth page four are:

The calculated breakaway force is 5615 lb at 2500 psi.

The calculated lifting capacity is 3165 lb at 2500 psi ( minimum capacity over the full range of motion?).
In top shape, a 4020 has about 2000 psi after the priority valve, 80 percent of 3165 = 2532 lb
minus 72 inch bucket weight = 450 lb
minus grappel weight = 800 lb
Leaves 1282 lb.
Stalling with a 1700 pound load in a high raised position sounds about right. Look how the angle between the lift cylinder and the boom is reduced as the loader is raised.
 
Here?s my 67 4020 lofting two 1700 pound square
bales of hay it has two 3 inch cylinders id say
something is wrong with your loader or hydraulics
a256794.jpg
 
It does not sound like a pump issue to me, more like a low fluid issue.

Are the lift cylinders single acting?

Is the fluid full?

Was clutch out if synchro?
 
(quoted from post at 00:25:23 02/13/18) Here?s my 67 4020 lofting two 1700 pound square
bales of hay it has two 3 inch cylinders id say
something is wrong with your loader or hydraulics
a256794.jpg
mvphoto10704.jpg
 

Fyi the quarry told me the rock I had bought was 13lbs/sf and I had ordered 100sf of it but they supplied me with 130 so 130x13 is 1690 so around 1700lbs

I guess the main reason I'm supprised is I can pick up 1500lb round bales with grapple on and never noticed a strain and just didn't think about 200more lbs making a difference

I will screw in my joystick valve bypass all the way tonight when I get home and see if that makes any difference
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top