Bls repair
Senior Member
Jay E how did you make out with the 710?
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New JD 710 owner needs help. No crowd (dipperstick) power
- Thread starter Jay E.
- Start date
Here it is a couple of weeks later and I've spend several thousand and 40+ hours and I've got... NOTHING. Well that is not quite true. I have a first class education on how a closed center, radial pump destroke enabled, 2550 PSI standby pressure, john deere hydraulic system operates. I now own a $2000.00 flow tester, 6 500 PSI gauges, $300.0 worth of diagnostic tees, dozens of plugs and caps, a spagetti pallet full of hoses, $250.00 worth of new hydraulic oil, and every applicable John Deere manual I could buy and read.
I did not need to buy and install a $6000.00, 3000 series pump. I did not need to buy and install a $3000.00 complete control valve assembly. I did not need to buy and cylinders. So I guess I'm ahead. Both of them work perfectly, in fact the pump worked above spec.
As near as I can tell, these machines are just under performers. Could John Deere have inflated the specs to make a sale ? Naaah, they wouldn't do that.
Funny thing though. The 710 G has a pump that puts out 5000 PSI of pressure, about double what mine does. Yet it only has 30% more lifting power. Double the hydraulic pressure should result in double the force. The fact that it doesn't tells me that the 710D was never able to do what the chart says on 2550 PSI. So mine has 40% less lifting power than the chart, which is amazingly close to what it should have if doubling the pressure gives you what the G model has.
The machine is SO HEAVY. It is clumsy to use and is not agile. Because it is heavy, it masks the power it has, so even though it may be digging as well as a 410 (which I havent put it directly against yet) it feels slow and doggy and underpowered. If I could put on 410 sized buckets it would help a lot because the geometry would be much better. I may figure out how to do that, it could just be a matter of machining undersized pin bushings.
Final word. I'm going to turn up the pump to 2800 PSI. 300 more should help the power, but makes operating it very abrupt as its designed to move at 2550. It will be bypassing in swing and boom down, but that is just too bad. If I could I would crank it all the way to 3000, but then it would heat up and wear out quickly as every thing will be bypassing.
Thank you to everyone who responded, a lot of your input was right on the money.
If I can find a nice 410G I'm going to send this one down the road. Good luck if you own one.
I did not need to buy and install a $6000.00, 3000 series pump. I did not need to buy and install a $3000.00 complete control valve assembly. I did not need to buy and cylinders. So I guess I'm ahead. Both of them work perfectly, in fact the pump worked above spec.
As near as I can tell, these machines are just under performers. Could John Deere have inflated the specs to make a sale ? Naaah, they wouldn't do that.
Funny thing though. The 710 G has a pump that puts out 5000 PSI of pressure, about double what mine does. Yet it only has 30% more lifting power. Double the hydraulic pressure should result in double the force. The fact that it doesn't tells me that the 710D was never able to do what the chart says on 2550 PSI. So mine has 40% less lifting power than the chart, which is amazingly close to what it should have if doubling the pressure gives you what the G model has.
The machine is SO HEAVY. It is clumsy to use and is not agile. Because it is heavy, it masks the power it has, so even though it may be digging as well as a 410 (which I havent put it directly against yet) it feels slow and doggy and underpowered. If I could put on 410 sized buckets it would help a lot because the geometry would be much better. I may figure out how to do that, it could just be a matter of machining undersized pin bushings.
Final word. I'm going to turn up the pump to 2800 PSI. 300 more should help the power, but makes operating it very abrupt as its designed to move at 2550. It will be bypassing in swing and boom down, but that is just too bad. If I could I would crank it all the way to 3000, but then it would heat up and wear out quickly as every thing will be bypassing.
Thank you to everyone who responded, a lot of your input was right on the money.
If I can find a nice 410G I'm going to send this one down the road. Good luck if you own one.
Last edited:
Tinkerer
Senior Member
Good grief Jay !
That is one of the saddest things about any T/L/B I have ever read. Not only the lost money and time, but to go through all that and end up with a piece of near useless S***. It has to extremely frustrating.
That is one of the saddest things about any T/L/B I have ever read. Not only the lost money and time, but to go through all that and end up with a piece of near useless S***. It has to extremely frustrating.
redneckracin
Senior Member
dam, that is so disheartening. I'd never look at a 710 again!
Saga continues. Today I went to work it and the engine was down on power. It simply would not govern itself into a stable RPM. Started with the fuel delivery ( filter, hoses, seals) and went all the way through the diagnosis. Valves were so far out it appeared they had never been adjusted since new. In the end the only thing left is the pump, finally took the injector pump out to have it rebuilt.
The last and final post. The new pump was installed and what a difference it made. Ity turns out that these six cylinder engines are pretty highly stressed and if the engine is not working PERFECTLY, the power to the hydraulics is uneven and they work like ****. So along with everything else that I did, I finally have a machine that is smooth and powerful. It still wont lift to spec, but it is good enough for me.
BUT WAIT.., After 20 gallons I've developed a popping through the exhaust and now everything is running like crap again. Bottom line, fix everything hydraulic and mike sure the engine purrs. If not, find my next thread, hopefully we can fix the miss.
BUT WAIT.., After 20 gallons I've developed a popping through the exhaust and now everything is running like crap again. Bottom line, fix everything hydraulic and mike sure the engine purrs. If not, find my next thread, hopefully we can fix the miss.
Willie B
Senior Member
My 410 might be completely different. The pump builds pressure against closed valves. When it reaches a specified pressure, the pressurized crankcase of the rotary pump overcomes the springs, and pistons don't return toward center. A closed center machine varries pump volume to maintain high pressure to each valve. As the moving of oil is what consumes horsepower, these systems are very efficient, and they start easily, as a few revolutions of the engine builds this pressure, then pump pistons stop moving.
Mine leaked through the spools in three of the backhoe valve sections making it function like an open center system. In my case this rendered the pump unable to satisfy the steering priority valve. Net result was no pressure at the cylinder. If you have pressure at the crowd cylinder, but no movement, I believe you have a bad cylinder seal on the piston.
An infra red camera will confirm. Start the engine cold. as oil warms, check what parts get warm. If the crowd cylinder isn't moving when you try, either oil is flowing where it shouldn't, or the piston is stuck. I'd guess oil is flowing around the piston inside the crowd cylinder. The pump is unable to keep up with the leakage to the reservoir.
Mine leaked through the spools in three of the backhoe valve sections making it function like an open center system. In my case this rendered the pump unable to satisfy the steering priority valve. Net result was no pressure at the cylinder. If you have pressure at the crowd cylinder, but no movement, I believe you have a bad cylinder seal on the piston.
An infra red camera will confirm. Start the engine cold. as oil warms, check what parts get warm. If the crowd cylinder isn't moving when you try, either oil is flowing where it shouldn't, or the piston is stuck. I'd guess oil is flowing around the piston inside the crowd cylinder. The pump is unable to keep up with the leakage to the reservoir.