1976 510 While Using The Backhoe Sometimes It Just Has No Power To Dig. I Have Found That If Trying To Curl The Bucket Or Uncurl If I Just Hit The Boom Lever Up Or Down It Will Get More Pressure To The Bucket For A Second. Same Thing With The Dipper. If You Try To Use Just One Sometimes It Has The Power It Should Other Times It Will Just Sit, Does Not Lug The Engine At All. Doesnt Matter Engine Speed. I Put A Pressure Gauge On Pump It Has Just A Little Over 2000 Psi. Have Changed All 3 Hyd Filters. Replaced All The O Rings On The Spool Valves And Looked At Valves No Scarring Or Wear. Steering Is Easy. Can Pull Into Dirt Pile With Diff Locked And It Will Spin Both Rear Tires Without Killing Engine. Any Ideas???
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Older Jd 510 Weak Hydraulics Intermitent
- Thread starter BUFFALERO
- Start date
Well i replaced the stroke valve 479.00 and took the pump completely apart, no problems in the pump bougth an overhaul kit for it and put it in. Took a pressure reading on standby the pump has 2300 psi. The transmission pump output is 170 psi. I still have the same problem. If i take and curl the backhoe bucket all the way or dump it all the way i cannot get it to go to bypass it just quits moving but does not strain the pumpno matter how long i hold it the same is true of the crowd. Anybody got any ideas.
JackDeere
Active Member
Just to hazard a guess, you might want to look at the priority valve. Maybe reach around and try the steering while the bucket is stalled.
Well i checked the priority valve. I hooked a pressure guage to it it was only reading 1200 psi while i worked the bucket so i added 2 thin shims inside brought it up to 1400 psi. Accoding to the book it should have 1450 psi but when i added a 3rd shim it was a little over 1500 psi. I didn't want to blow a hose or anything on the steering so i just left it a 1400. My backhoe still does the same thing?
Ok. As I say, I don't know the JD system so I could be completely wrong, but if it was a cat, I would be looking at the load sensing circuit.
This senses pressure in each individual circuit, then whatever circuit has the most pressure, sends this signal back to the pump which then upstrokes accordingly.
It does this via a "resolver network" (In Cat-speak). A resolver is a hydraulic logic valve which senses two pressures and delivers the higher pressure. In your case I think you may have a problem with the boom resolver. When you are using the bucket or dipper, the signal pressure is bypassing the boom resolver and going straight to tank, but when you use the boom, this is sending the correct signal to upstroke the pump.
Anyhoo, to cut to the chase, try taking a look at your valve block in the area of the boom spool section. You may see a small (approx 7/16) plug or two. (Each valve section should look roughly similar with the same plugs). Remove these plugs in turn and take a look. Some may be only blanking plugs but hopefully behind one you may find a tiny spool and/or ball-bearing and/or spring. This is the resolver. Look for sticking parts, broken O rings, broken spring, bad seat where the ball sits. If you need to, remove one from another valve section to compare.
As I say, I could be totally wrong but that's how I would approach a cat with your symptoms.
Hope this helps.
This senses pressure in each individual circuit, then whatever circuit has the most pressure, sends this signal back to the pump which then upstrokes accordingly.
It does this via a "resolver network" (In Cat-speak). A resolver is a hydraulic logic valve which senses two pressures and delivers the higher pressure. In your case I think you may have a problem with the boom resolver. When you are using the bucket or dipper, the signal pressure is bypassing the boom resolver and going straight to tank, but when you use the boom, this is sending the correct signal to upstroke the pump.
Anyhoo, to cut to the chase, try taking a look at your valve block in the area of the boom spool section. You may see a small (approx 7/16) plug or two. (Each valve section should look roughly similar with the same plugs). Remove these plugs in turn and take a look. Some may be only blanking plugs but hopefully behind one you may find a tiny spool and/or ball-bearing and/or spring. This is the resolver. Look for sticking parts, broken O rings, broken spring, bad seat where the ball sits. If you need to, remove one from another valve section to compare.
As I say, I could be totally wrong but that's how I would approach a cat with your symptoms.
Hope this helps.
Well i finaly got to work on my backhoe again. I removed the whole valve block lot heavier than i thought. There are 3 plugs 2 are on the swing valve in the back and 1 is on the boom on the bottom back they look just like a vale in a gas engine with a spring to keep them seated. All 3 springs are the same. No pitting or sticking. I have ordered the o rings to put the valve block back together. I removed all the valves kept them in order cleaned everything real good looked in all the housings for any cracks or defects and found nothing wrong.
Ok That's me out of ideas without looking first-hand. It still sounds like the load sensing circuit though.
Anyone here know how these Deeres get the pump to upstroke?
Is there a small hydraulic line going to the pump? This will be the line that tells the pump to upstroke, or maybe it's done electrically? Does the pump have any sort of solenoid? Find out what makes the pump upstroke and trace it to wherever it interacts with the backhoe circuit.
Sorry I can't be any more help...
Anyone here know how these Deeres get the pump to upstroke?
Is there a small hydraulic line going to the pump? This will be the line that tells the pump to upstroke, or maybe it's done electrically? Does the pump have any sort of solenoid? Find out what makes the pump upstroke and trace it to wherever it interacts with the backhoe circuit.
Sorry I can't be any more help...
Well i got it fixed !!!!! Since i could't adjust the standby pressure up above 2000 psi i removed the plug with the adjusting bolt and i put 3 thin washers under the spring. That raised my standby pressure up to 2600 psi. Now if i dig into the ground real hard with the stabalizers down and rear wheels of the ground i can actually pull the front wheels off the ground now this has enough power to break itself if not carefull. Thank you so much for all the help from everyone.
tx_swordguy
Active Member
I realize this is an old thread but I am trying to understand some terms so I can relate them to my own FORD 555. Is the "standby pressure" BUFFALERO referred to the same as the main reliefe valve pressure in regards to the bachoe part of the tractor?
Not sure on a ford some backhoes have another pressure relief valve before actually going into the manifold for the backhoe valves. The best way i found to see if your pressure is to low is to see if any of the relief valves will pop and go into bypass. The ones with the lowest settings are the swing and the crowd. Even lower should be the front bucket dump. If you put the hoe on the ground lift just the wieght of the machine leave the tiresjust on the ground but have the stabalizers down,now try the swing if you don't hear it go into bypass in other words you will hear it sound like there's a leak then the pressure is to low. Then try the bucket dump on the front loader on most deeres these relief valves range from 1400-1700 psi to avoid bending the rams put the front bucket on the ground flat like you were going into a pile then just use the dump to try to pickup the front end with the backhoe still on the ground it should go into bypass, the relief valve pressure is stamped in the top where you put the wrench to remove it at least it is on deeres i hope this helps.
tx_swordguy
Active Member
Thanks Buff,, I guess what I am asking. I have a main relief valve that is on the end of the valve block that controls the hoe part of the tractor. Manual states (if I remember right) it should be set at about 2550 psi. Then each circuit (dipper/crowd,bucket,lift/boom) has a relief as well that is seperate from the main relief. I am asking if the standby pressure you refer to ,would be the same pressure that my manual is talking about that is controlled by the main relief valve? I have not found a "standby" pressure talked about in the manual yet. I am going to get a guage and start checking my pressures and was going to start with the main and go from there. What you did with your "standby" pressure appeared to work for you and I am wondering if the same might be true with my "main relief valve". Forgive me if I am not calling things by proper names, that is why I ask this
bowlerman
Member
i think i have the same problem with my jd710b, i have been looking and looking. when you go to dig or lift machine it just gives up, rebuilt pump and still no help. what adjusting bolt? on thee hydraulic pump? thanks
Jerbo
Member
I know this is an old thread, but i think ihave the same problem to on my jd410. Trying to dig sometimes the bucket just stays where its at, won't curl and no load on the engine at all.
What bolt do you think he was referring to for adding shims.
What bolt do you think he was referring to for adding shims.
Jerbo, there's some old gems of true mechanical wisdom on this forum, but this thread AINT one of them.
Please disregard anything previously written in this thread, and start your own describing your symptoms some more.
It is completely normal for the backhoe to just stop and NOT load the engine when you reach the max pressure on the pump. Just curl the bucket in or out all the way and listen to the engine when it stops, no load and no squealing relief valve because no pumping, the pump can't tell the difference between standby pressure and stalled pressure.
Please disregard anything previously written in this thread, and start your own describing your symptoms some more.
It is completely normal for the backhoe to just stop and NOT load the engine when you reach the max pressure on the pump. Just curl the bucket in or out all the way and listen to the engine when it stops, no load and no squealing relief valve because no pumping, the pump can't tell the difference between standby pressure and stalled pressure.
Jerbo
Member
Ok, thanks. I just bought this and this was the first time i actually used it and it seemed to me that the hydraulics wouldn't just stop like that. When i curled the bucket it would go ahead and work. I had to work both sticks, but i finally got the hole dug. I was burying a dead cow 
It'll just take some practice i guess. Everything else seems to be working ok. So far i'm happy with it.
It'll just take some practice i guess. Everything else seems to be working ok. So far i'm happy with it.That sounds normal. The pressure regulation is within the pump itself, it just stops pumping just like if none of the control valves are opened, unlike an open center system where you expect to hear a relief whining when you stall the hydraulics.
You want to use the functions at the same time to take an even slice to dig effectively (in the "middle of the pump curve"). Curl the bucket to keep the teeth at the same low angle into the dirt, use the stick to power the bucket through the dirt, and lift the boom to keep the slice even. You're overstressing the hoe by stalling it out just to dig a hole. Save the grunting for the stumps.
You want to use the functions at the same time to take an even slice to dig effectively (in the "middle of the pump curve"). Curl the bucket to keep the teeth at the same low angle into the dirt, use the stick to power the bucket through the dirt, and lift the boom to keep the slice even. You're overstressing the hoe by stalling it out just to dig a hole. Save the grunting for the stumps.