JD 790 300 loader

[dirt ditch]

A little shimmin' gets ya grinnin'.


790 + 420 lbs forks + 3 or 4 year old CRP grass bales, handled them with no problems. Have no idea how much they weigh now. When the bales were new they weighed 1000 lbs.
Just getting rid of the few that are around here.


JD says no round bales with the 790 and 300

 

[Whitey]

Adding shims will increase pressure to the whole hydraulic system of the tractor, not just the loader but also the 3 point.

OK.......just a question to that........I have a 770 with a 70 FEL and 7 BH.....can I get a shim kit for it and will it affect the BH too?

 

[kennyd]

OK.......just a question to that........I have a 770 with a 70 FEL and 7 BH.....can I get a shim kit for it and will it affect the BH too?

Read post's #43 and #44.

 

[Whitey]

Read post's #43 and #44.

Thanx...................

 

[nmu98]

What about the backhoe? My tech manual says that my #7 BH has a main system releif valve setting of about 1900 psi. It would seem that if the tractor pressure were increased, there still wouldn't be any change in the BH performance.

Welcome to TBN


The valve set on the backhoe should have it's own relief valve so you are correct.

Thanx...................

Whitey, Kenny answered your question... Why the negative attitude?????

 

[kebo]

Whitey, Kenny answered your question... Why the negative attitude?????

I think it was because he didn't get the answer he wanted to hear. His backhoe would still be limited by a separate relief valve set to relieve at a lower pressure. I think he was hoping that by adding the shims it would increase the backhoe pressures. That was how I took it anyway.

 

[kebo]

Ok, I ordered the shim kit at my local JD dealer earlier this week and it came in today. They were kind enough to call me and let me know too. Actually, I ordered two packs, appears to be (4) shims in each pack. Have not opened or looked at them closely to tell if they are all the same thickness or not. I also got an extra O ring, but I think I got the wrong one. I got the one in the exploded assy view that's #16. I didn't see the #21 O ring beneath it, that's probably the one that I might need right?? Might have to call back and see if they have that one as well.

Also, I stopped by a local hydraulic hose and fitting shop convienently on the way home from work today and he had EXACTLY what I needed for the gauge. He sold me a 0-3000PSI gauge for $18, plus the quick-connect fitting for another $9, and them some change for a bushing to mate the two up. All for $30 bucks with tax. Got some pipe tape at Lowes and put it all together this evening. I may attempt this tomorrow if I get time, if not, it'll be next weekend before I mess with it.

Oh yeah, the JD dealer had t-shirts and caps reduced to $10 each. I had to get one of each and then scurry on out of there before I dropped anymore cash on the counter. LOTS of stuff in there I don't really need but I sure could use!!!

 

[dirt ditch]

OK.......just a question to that........I have a 770 with a 70 FEL and 7 BH.....can I get a shim kit for it and will it affect the BH too?

From what I under stand about the mfwd 790 is that the same dual gear hydraulic pump is used on some other JD compacts with a factory setting of 2500 psi. So increasing the hydraulic pressure of the 790 from 2050 to 2500 psi will not damage the pump. Does the 770 have the same dual gear pump as the mfwd 790? I don't know, but you should probably find out before boosting the pressure.

 

[YesDeere]

Couldn't help myself, boosted mine to around 2900 psi. And holy hel* will it pick up a pallet of wood now with the three point forks! Now I have to remeber to counter balance with some weight in the fel. Only like wheelstands on my old three wheeler. We'll see how it holds up.

 

[dirt ditch]

2900psi