JD.990 increasing loader lift capacity

mjc · Dec 27, 2008

Has anyone increased the hydraulic pressure on a 990 ,
dealer says you can't, looking for more lift from loader.( 300cx)
many thanks

dirtworksequip · Dec 27, 2008

Almost everyone wants more lift from their machine. You need to get a good gauge to check to make sure your hyd pump is within specs. Then after you have that info you can do what you want. Either setting it up to max. spec or going above. I worked for a company that set all their 100 ton Cat trucks hyd pumps up so they would easily dump between 115 and 120 tons. Needless to say those pumps failed within a short time. So, you need to decide if the extra lift you might gain is worth the expense of a failed hyd. pump if you have to exceed the factory spec to get the need lift.

Sincerely, Dirt

mjc · Dec 27, 2008

Thanks for the help dirt, This hydraulic system is putting out aprox 2250 psi,
In older machines when you load the fel you could gauge what
you could lift by your rpm level, or engine load, this machine does not labor much at all.
While lifting materials in the fel it just stops lifting , when it meets that cut off point , as far as lifting it lifts what the manual says , my problem is when loading material that is wet or very dense to load into a smaller dump truck it will pick high as long as you don't level out the bucket which does not help much when your hood is catching material on the way up.
Many thanks. . Happy New Year to all. mjc

radman1 · Dec 28, 2008

2250 psi seems low to me. Most newer tractors will have at least 2500 psi. My JD 3720 was about 2300-2400 and was suppose to be 2500. I changed the set screw to about 2900 psi. 15% change makes a noticeable difference in the lift. It is uncommon for me to use the loader at max very often. Less than 5% of FEL time requires max lift for my usage. My set screw was on the hydraulic control valve. It was a bolt with locking/set nut. Backed off the nut and turned it in 1-2 turn. Recheck the pressure before tighting the set nut.

mjc · Dec 28, 2008

Thanks Radman;
I will double check the hydraulic control valve and see if there is a
set screw there, the hydraulic system on the 90 series I think are very similar ,
I am thinking that I may have to use a shim for the adjustment.the manual
is calling for hydraulic system pressure of 2262 psi which I felt was kind of low for this size machine . Are you using a 400 series fel on your 3720?
Many thanks. mjc

radman1 · Dec 28, 2008

mjc

I have the 300cx loader. Biggest loader offered for the 3x20 series.

Willl · Dec 28, 2008

Item #18 is your system relief valve.

Item # 21 is your shim kit, part #CH13559.

mjc · Dec 28, 2008

Thanks Willl, Thats a big help, I think I will try one shim , check the pressure
and see what that does . That grapple is impressive did you have to install
a faucie valve to run the grapple? Also that backhoe thumb looks like it works well , I am thinking about a thumb for the 8b that I have.
Many thanks. mjc