John Deere 410 Backhoe hydraulics bleed down
John Deere 410 Backhoe hydraulics bleed down
I have an early '70's JD 410 backhoe I purchased almost 5 years ago. I use it around the farm and never in a hurry.
I didn't know what to look for before purchase. So the front bucket being really, really slow after warm up went unnoticed. As did the excessive bleed down and lack of power in the rest of the hydraulic systems.
I tested the pressures in the system a couple of years ago. 1500 lbs. cold, 1250 warm. System is supposed to be at 2300-2400 lbs. I don't have a flow meter, but was told the pump was replaced about 5 years before I purchased the machine. He gave me a box containing the old pump.
Since every system was bleeding down and I had a ton of oil coming out of the return line with all the valves in neutral, I guessed it was in the valves. I purchased rebuild kits from John Deere.
Today I pulled the valves. Looking at the spool through the port, I see that "97" has been inscribed on all the spools.
Questions: Does that mean that someone rebuilt the valves in 1997? I wouldn't think they'd need it now. If that is the case, I'd just replace the "O" rings between the valves and put them back.
If it isn't the valves, does that indicate I have to rebuild all the cylinders? Or could there be some other problem to look at?
Thanks,
Brian
I didn't know what to look for before purchase. So the front bucket being really, really slow after warm up went unnoticed. As did the excessive bleed down and lack of power in the rest of the hydraulic systems.
I tested the pressures in the system a couple of years ago. 1500 lbs. cold, 1250 warm. System is supposed to be at 2300-2400 lbs. I don't have a flow meter, but was told the pump was replaced about 5 years before I purchased the machine. He gave me a box containing the old pump.
Since every system was bleeding down and I had a ton of oil coming out of the return line with all the valves in neutral, I guessed it was in the valves. I purchased rebuild kits from John Deere.
Today I pulled the valves. Looking at the spool through the port, I see that "97" has been inscribed on all the spools.
Questions: Does that mean that someone rebuilt the valves in 1997? I wouldn't think they'd need it now. If that is the case, I'd just replace the "O" rings between the valves and put them back.
If it isn't the valves, does that indicate I have to rebuild all the cylinders? Or could there be some other problem to look at?
Thanks,
Brian
'63 2010 Dozer, '44 Model B Tractor,'65 2010 Tractor, '55 40c crawler, '77 2240 Orchard Tractor.
John Deere 410 Backhoe hydraulics bleed down
Lavoy, thanks for the suggestion.
I blocked off the lines going to the backhoe valve block and the pressure at the test port on the pump jumped to just a hair over 2400 lbs. cold.
I don't think all the valves would go bad, so I'm trying to figure out a way to test each valve independently for internal leakage.
I opened up the 1st valve (right stabilizer) and could see nothing wrong with the spool.
I'd like to avoid opening up all the valves. I really don't know what to look for other than a really sloppy fit.
B.
I blocked off the lines going to the backhoe valve block and the pressure at the test port on the pump jumped to just a hair over 2400 lbs. cold.
I don't think all the valves would go bad, so I'm trying to figure out a way to test each valve independently for internal leakage.
I opened up the 1st valve (right stabilizer) and could see nothing wrong with the spool.
I'd like to avoid opening up all the valves. I really don't know what to look for other than a really sloppy fit.
B.
'63 2010 Dozer, '44 Model B Tractor,'65 2010 Tractor, '55 40c crawler, '77 2240 Orchard Tractor.
John Deere 410 Backhoe hydraulics bleed down
Ken,
Thanks for your insight and for taking the time on the detailed reply.
I am currently looking for used replacement valves or an entire valve block. It looks like mine can be rebuilt for $600 to $900 apiece, though I can't justify spending that kind of money on my play toy right now.
I may try and find a high pressure shutoff valve to plumb in. That would allow me to use the front loader for more than a wheelbarrow.
Brian
Thanks for your insight and for taking the time on the detailed reply.
I am currently looking for used replacement valves or an entire valve block. It looks like mine can be rebuilt for $600 to $900 apiece, though I can't justify spending that kind of money on my play toy right now.
I may try and find a high pressure shutoff valve to plumb in. That would allow me to use the front loader for more than a wheelbarrow.
Brian
'63 2010 Dozer, '44 Model B Tractor,'65 2010 Tractor, '55 40c crawler, '77 2240 Orchard Tractor.
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Did you check the oil supply side of the pump? If there is some kind of restriction you will not get the psi or gpm. I've seen the supply line crushed, there is a hose in the loop i've seen the hose come apart inside and restrict the flow. check the screen on the pick up side for restriction. I've seen water laden oil restrict the flow. Does the functions chater or cavitat when u use them?
if you have a closed centre system you can dead head each lever in a safe direction all at the same time, watch your pressure guage, when you dead head the offending circuit the pressure will jump to 2400 psi, then you know which valve is the bad one. is your backhoe control valve seperate from the stabilizer control valve? i have found that the stabilizer control valves when they are seperate from the backhoe control valves can be a cause of a lot of backhoe problems because they use the same supply line, but since they have cross-piloted check valves to hold the stabilizer in one position unitl you ask it to move it often gets overlooked.
1964 JD 4020
1974 JD 420B
1942 JD BR
1941 Cat D6
2008 Kubota B2320
1974 JD 420B
1942 JD BR
1941 Cat D6
2008 Kubota B2320
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