Newbie with JD 870 non-working hydraulics

[Dave W R]

I have a JD 870,it has loader and power steering,it had slow hydraulics,I changed filter,hydraulics wouldn`t work,I drained system,cleaned screen[which was very clean] ,installed new fluid,hydraulics wouldn`t work.I even tried to prime pump by pouring fluid in return port.
I thought maybe a defective filter,bought and installed new filter,still won`t work
I have just ran out of things I can think of.
3 point and steering both won`t work.
Any ideas would be appreciated.
Doesn`t seem logical both pumps to go out at same time.
Thanks,Dave

 

[Leejohn]

If it is a stacked pump(2 in 1) it could be the coupler or drive gear.

 

[chriswheeler]

Hi Dave, I have a 970 and just had a look at the parts catalog. ( same pump ) Does your power steering still work ?? ( sounds like that's a no ) If it doesn't, the hyd pump is of a stacked design, and I'd be looking at the pump after cleaning the suction screen and changing the filter, re-filling with the JD Low Viscosity High Guard fluid. Most times the system self primes after refilling. but sometimes the air in the lines needs a place to go so the pump will take a suction. Holding the loader control stick in the up position for a few seconds should do this, no need to open a line. If it does take a suction, work the loader and 3 point until all air is out. If that doesn't work, time to remove the pump and look at it hard, see if you find something broken or worn out. Forgot to mention it sure could be the part where your tractor has a power beyond connection ( I need one to run the backhoe on mine ) and somehow your tractor got run with a hose disconnected dead-heading the pump. In that case, something would shear inside the pump. Could be a sheared drive key or coupler. May not be the pump, but most likely.
Chris

 

[Dave W R]

I think my problem is I put the wrong fluid in it,it said it was approved for JD,but it didn`t specify low viscosity.
Take a little drive tomorrow to JD dealer to get the right oil.
I will check back with results.
Thanks for the imput,just hope it was my screwup.
Dave

 

[chriswheeler]

Still should have been some pressure Dave. The hyd fluid that JD uses, Low Viscosity High Guard, is a modified AW-32 with some stuff added to lube the pump and seals. The old stuff JD used was JD 303. The 303 you can get at Walmart for under $50 per 5 gallons. The JD Low Viscosity High Guard from JD dealers is around $90 per five gallons. I choose to use the expensive stuff from JD knowing that saving some wear on my tractor is worth the price. You will need 7 gallons or so to fill the sump, 2 ea. 5 gallon pails. I'm inclined to think you still would have seen some pressure from the pump. Changing to the proper hyd fluid is a good thing, won't hurt it, but I think it's more likely something else.
Chris

 

[Dave W R]

Still should have been some pressure Dave. The hyd fluid that JD uses, Low Viscosity High Guard, is a modified AW-32 with some stuff added to lube the pump and seals. The old stuff JD used was JD 303. The 303 you can get at Walmart for under $50 per 5 gallons. The JD Low Viscosity High Guard from JD dealers is around $90 per five gallons. I choose to use the expensive stuff from JD knowing that saving some wear on my tractor is worth the price. You will need 7 gallons or so to fill the sump, 2 ea. 5 gallon pails. I'm inclined to think you still would have seen some pressure from the pump. Changing to the proper hyd fluid is a good thing, won't hurt it, but I think it's more likely something else.
Chris

I hope not,the price of fluid is lot cheaper than pumps.
Dave

 

[Dave W R]

OK,went to JD dealer,$120.00 later I have 6 gal HIgard fluid ,installed it and hydraulics primed up bled out and now work just fine.
From now on when they say a specific product for their equipment,I will listen.
Thanks for the imput,
Dave

 

[chriswheeler]

Great Dave. Replacing that pump would have been very costly. I'm always tempted to get the cheap Walmart stuff, but after getting a nicer tractor I've decided to always error on the side of the tractor and buy the good stuff. My old YM3000 and JD950 did fine with it but had a much simpler layout. One other thing, your JD dealer sure charges less for that stuff than mine here.
Chris