850 with 3 point problem

[lilburr]

recently purchased a 1979 JD 850 (late June 2013) and after limited use with a boxblade, I have been on the mend and have not been able to use the tractor.

I did some basic maintenance after purchase like hydraulic fluid change / screen clean, air cleaner. I did notice a leak of hydraulics, nothing drastic, under the seat and since it was a little milky, thats why I changed the fluid. It leaks enough to wipe up the area under the seat and not enough to puddle on the ground.

So I cranked her up yesterday and after starting to do some light work close to the barn, got very little response from the three point lever. The blade raised just enough for a minimum clearance off the ground to get back to the barn and it was very slow to get that several inches offa the ground.

Several days ago, I had cranked the tractor (after 6 weks or so of non activity) and idled it without driving. During that warm up, I also raised and lowered the three point several times, successfully. It has been a little sluggish acting since I got it, a little slow to react from what I'm used to but I just have not had much time on this seat yet to question.

One thing I've noticed is when running and sitting at idle, it sounds like the PTO is spinning but this is when PTO is not engaged (and not visibly running). When depressing the clutch, it sounded like it stopped, the spinning sound stopped.

I have set and re-set the knob under the seat that regulates the three point action but got no real differing response yesterday.

Anybody seen this ?

 

[wolftree]

Does your tractor have a filter on the hydraulic system?

 

[lilburr]

not that I know of; a screen at the bottom was removed and cleaned when I changed the fluid and Ive heard the screen acted as filter in this model, maybe ?

 

[BATTY54]

The knob under the seat is just a shutoff valve, there should be a small lever type thing just above it. This lever will control your rate of drop and speed, maybe not making myself clear. The knob should be open all the way always except for cold weather warm ups for the hydraulic fluid as specified in the operators manual. I will try to get a picture and post it later today.

 

[wolftree]

lilburr,

If your tractor has power steering, then according to an older posting here at TBN, you should have a hydraulic filter just ahead of the axle on left side. According to that posting, you want to drain hydraulic system BEFORE removing the filter.

If you do not have power steering, then BATTY54 is probably correct about the lever valve not being open.

If you did not get an operators manual, go to John Deere and order one,$20 or so.

 

[BATTY54]

The red lever is the speed of drop control for lighter or heavier implements. Forward slows the rockshaft drop, rearward increases the speed of drop from the owners manual.

 

[lilburr]

yes, I have noticed the red lever, I had not recognized as a lever though. It is and has been in a vertical position like yer photo. I am understanding this as the position. No power steering. I am having a hard time finding manual believe it or not. (although I have not yet visited a dealership).

After cranking this evening, it was very sluggish, it did lift a couple times (while on a maybe 2000 rpm idle) but lost lift pretty much after a couple.

thanks, burr

 

[jd110]

You mentioned you had milky fluid when you bought it. How does the fluid look now? Sometimes it takes a coulpe of changes to get the water out completely, plus if it sits outside, it may have gotten water in it again. Either way, I think I would start by draining the oil and checking the screen again. Moisture in the system can gum up the screen pretty quick. If the screen is clean, then I suspect you have a worn hydraulic pump. The 850 has a small pump to start with and when they get worn, they lose flow quickly. If you replace it, get the larger pump that is available.

 

[lilburr]

where (on tractor) is the hydraulic pump located ? The picture above ?

Before I got the tractor, it had been stored outside in the weather. Since, I have stored it under a roof in an open type barn.

 

[wolftree]

lilburr,

1) Pickup your telephone and call your John Deere dealer, or any John Deere dealer and order the operating manual for your tractor. Have it sent to your home if possible.

2) Be sure rounded hand valve is in open position. Try moving the red lever valve to both positions and operating your 3 point hitch in each position.

3) Did you use John Deere Hydraulic fluid to refill hydraulic resevoir or something else?

4) The hydraulic pump is mounted on the engine of the tractor. Usually near the front and on the side. Follow the hydraulic lines coming from the rear of the tractor. Those will lead to the pump. There should be two lines, output and return lines.

5) It is possible you have air in the hydraulic system and need to work the 3 point many times to work the air out.

6) Do you have rear or front hydraulic remotes? If so, do they work?