JD 790 300 loader

JJZ 109 · Feb 12, 2009

Gauge put together and working fine. Box stock the tractor is showing 2200 psi at the QC that curls the bucket. Will most likely only install 2 of the 4 shims and see what I get.
It hasn't become such a priority now that I've been shopping for a Kubota B3030 HSDC cab tractor. But I may not find the right deal so the shimming may come back into play and the Deere stays home.

kennyd · Feb 12, 2009

JJZ 109 said:
It hasn't become such a priority now that I've been shopping for a Kubota B3030 HSDC cab tractor.

That is sad news...

kennyd · Feb 13, 2009

K7LN said:
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.

kebo · Feb 14, 2009

Well, now you all got me interested in upgrading the hydraulic pressure on my 790 so I called my local JD dealer this morning. He didn't have the shim kit in stock, but he's going to order me (2) packs @ $3.78 each. They'll be here on Wednesday. I also stopped by my local TSC for the pressure guage and they didn't have one, nor did they show it in their latest TSC catalog either! Foggy, do you know the SKU number of the pressure guage you got at your TSC??? If you have it, either post it or send me a PM with that number. Thanks.

I did stop by a NAPA after I left TSC and they listed one for $25, but he would have to order it too. So, I'll have to keep looking for a guage at a reasonable price. I hate to spend more than I have to for something I will only use one time. I haven't tried the AutoZones or Advance parts stores yet. If they carry one, it should be cheaper than NAPA's price. Might do that later today or tomorrow.

Keith

JJZ 109 · Feb 14, 2009

kebo said:
I did stop by a NAPA after I left TSC and they listed one for $25, but he would have to order it too. So, I'll have to keep looking for a guage at a reasonable price.

I did go the $25 gauge route at NAPA. Had to order it but my local store get most everything in the very next morning. Keep in mind you'll have the rest of your expense to plumb the thing up unless you happen to have stuff laying around like I did.
Even then I still had to get the male QC from Deere and have another end to fit the QC crimped on at a hydraulic hose place.
As someone mentioned earlier, I never had a problem lifting the front end with stock pressure. I just wanted to boost it up a little bit so that I could easier lift my finish mower and brush hog when they are on pallets in the off season.

foggy1111 · Feb 14, 2009

Kebo....I didnt get the guage at Tractor Supply....I got mine at our local fleet and farm supply store here in Minnesota (Runnings) whom keeps a fair supply of common stuff on hand. My tractor is across town...but I will post the guage manufacturer as soon as I go there. I think these guages should be commonly available.

kebo · Feb 14, 2009

foggy1111 said:
Kebo....I didnt get the guage at Tractor Supply....I got mine at our local fleet and farm supply store here in Minnesota (Runnings) whom keeps a fair supply of common stuff on hand. My tractor is across town...but I will post the guage manufacturer as soon as I go there. I think these guages should be commonly available.

Oops, my bad then. I thought I had read where you got your gauge at TSC. Obviously it was someone else. I'll keep checking around then. Thanks.
Keith

dirt ditch · Feb 14, 2009

kebo, here is a cheap 3000psi gauge that will work. They dont have the gauge I bought from them listed any more, but this one is only $12.95. It is made to mount in a panel, but for what you will be doing with it, it will work just fine. Here is a 5000psi gauge for $12.95 that will also work.

Burden Sales Surplus Center Item Detail

Burden Sales Surplus Center Item Detail

kebo · Feb 14, 2009

dirt ditch said:
kebo, here is a cheap 3000psi gauge that will work. They dont have the gauge I bought from them listed any more, but this one is only $12.95. It is made to mount in a panel, but for what you will be doing with it, it will work just fine. Here is a 5000psi gauge for $12.95 that will also work.

Burden Sales Surplus Center Item Detail

Burden Sales Surplus Center Item Detail

It looks like the hose connection to the panel mount guage (21-1637-BL) is a 1/4" NPT male, that should do the trick. I think I'll call them first thing Monday morning. If they can get it to me by next Friday, I'll go ahead and order it. Thanks!

Keith

dirt ditch · Feb 15, 2009

dirt ditch said:
Here is a 5000psi gauge for $12.95 that will also work.

Burden Sales Surplus Center Item Detail

Glade you caught my error kebo.This gauge would not work well because of the SAE 4 Bulkhead Connection it has. Posted in haste, did not read the description well enough. My bad

dirt ditch · Feb 16, 2009

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 · Feb 19, 2009

dirt ditch said:
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 · Feb 19, 2009

Whitey said:
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 · Feb 19, 2009

kennyd said:
Read post's #43 and #44.

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

nmu98 · Feb 20, 2009

K7LN said:
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.

kennyd said:
Welcome to TBN

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

Whitey said:
Thanx...................

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

kebo · Feb 20, 2009

nmu98 said:
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 · Feb 20, 2009

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 · Feb 21, 2009

Whitey said:
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 · Feb 23, 2009

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.