wood butcher

[mjc]

990 shim kit

I have a J.D. 990 tlb , I was wondering if anyone has installed a hydraulic shim kit
in a 990, I know that they make the shim kit for the 790 , but I can not find any listing for a shim kit for the 990 at the dealer. Or if any ideas how I could increase hydraulic pressure by 10 to 20%. Also has anyone had trouble with a
8b hoe sagging while in use ,( dipper stick and outriggers falling slightly while in use)? Many Thanks

 

[kennyd]

Welcome to TBN

BEFORE you worry about raising the pressure-get a gauge setup and find out what yours is set for now. I am not sure if the 990 uses shims or just a screw and jamb nut to set the PRV.

Cylinders leaking down is usually a sign that need rebuilding. Seal kits vary in price from $25 to $100 at the dealer or you can find a local shop to get the rebuilt.

Hopefully you will get some other views, your post title is a little strange

 

[mjc]

Thanks for the help Kennyd, Sorry about the post title , I will check the hydraulic pressure 1st, I believe it should be fairly close to the factory spec's,
I don't see any jamb nut to adjust the hydraulic pressure , thats way I am guessing it is like the 790 and uses a shim kit.
I did talk to the dealer about the back hoe , and their suggestion was to
install a back flow valve, Their thought was that it would be unlikely to be the seals because all the cylinders drop at the same rate , they don't drop that quickly but over an hour they drop 3-4 inches or so , this has done this since it was new.