DLTTrekkers-- Thanks for your reply. That was the adjustment I was making (2nd step in rockshaft setup after the Negative Stop Screw adjustment as listed in the manual) when the whole thing starting acting so weird that I stopped because it would not let the rockshaft lever stay in a lower position. Quite frankly, it just never occurred to me to go ahead and turn the screw one way or another to see what would happen. Maybe I'll try that when I get 'er cranked up again.
John Deere 1640 Strange Hydraulic Problem
- Thread starter Jimbo1640
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I want to thank everyone for their input on this. Tx Jim--you were right, the top had to come off.
After over a month of dealing with other matters here on the farm, was finally able to get back to it. Ordered a Rockshaft Seal Kit, new piston rings, new gasket for the top, and new washers for the Rate of Drop valve. Took the top off and went at it, changing out all O rings, washers, and piston seal, etc. Learned how to remove the valves and found what I believe was the culprit--a small piece of wire or a shaving from a steel washer that was trapped inside one of the valves. This would make sense considering the weird behavior of the hydraulics and the spraying of oil everywhere inside the Rockshaft when the lever was in the down position--the valve couldn't close! I was pleased that the piston showed very little scoring. Anyway, got it back together and it seems to work just fine so far--very reliable. Wish I done the new seal kit when I had the top off a few years ago.
This 1st image is of my jerry-rigged valve compressor--a short piece of 1/2" copper pipe around the valve stem allowing to gently compress with a c-clamp to access the snap ring.
Accessing the snap ring.
The valves removed, showing the replaced parts beside (the new ones were part of the Rockshaft seal kit). Note a small piece of wire near bottom right--that was up in the valve seat preventing the valve from closing.
Anyway--thanks for your help. Cheers!
After over a month of dealing with other matters here on the farm, was finally able to get back to it. Ordered a Rockshaft Seal Kit, new piston rings, new gasket for the top, and new washers for the Rate of Drop valve. Took the top off and went at it, changing out all O rings, washers, and piston seal, etc. Learned how to remove the valves and found what I believe was the culprit--a small piece of wire or a shaving from a steel washer that was trapped inside one of the valves. This would make sense considering the weird behavior of the hydraulics and the spraying of oil everywhere inside the Rockshaft when the lever was in the down position--the valve couldn't close! I was pleased that the piston showed very little scoring. Anyway, got it back together and it seems to work just fine so far--very reliable. Wish I done the new seal kit when I had the top off a few years ago.
This 1st image is of my jerry-rigged valve compressor--a short piece of 1/2" copper pipe around the valve stem allowing to gently compress with a c-clamp to access the snap ring.
Accessing the snap ring.
The valves removed, showing the replaced parts beside (the new ones were part of the Rockshaft seal kit). Note a small piece of wire near bottom right--that was up in the valve seat preventing the valve from closing.
Anyway--thanks for your help. Cheers!
Tx Jim
New Member
Thanks for update. I'm glad I could be of assistance & you got that hyd problem solved.
Jim
Jim
Zebrafive
Super Member
Thanks for the pictures, and copper pipe trick. I hope I do not have to go into my 2030 rockshaft cylinder or valve :thumbsup:
historyan1975
Silver Member
Hi...
There is a JD 1640, 4x4, from 1982, serial number: 428793... Now, I am looking for a new hydraulic pump... but I am confused. The tractor is made in Europe, I suppose it is not made in Spain... In my research, I found two types of pumps: with 23 CM2/min (1,4 Cu.Inch) flow (AR103036, AR 103033) and 12 cm3 (0,7 CU.In) flow (AR103035)... And, I soo that there exist an other type, more exactly 40 cm3/min. flow.....(AR39695, AR90459, AR97872)..
I supose the pump with 23CM2/min. would be good choose for this tractor, but I am not surre... Please, give me an advice....
Thanks, Benedek J.
There is a JD 1640, 4x4, from 1982, serial number: 428793... Now, I am looking for a new hydraulic pump... but I am confused. The tractor is made in Europe, I suppose it is not made in Spain... In my research, I found two types of pumps: with 23 CM2/min (1,4 Cu.Inch) flow (AR103036, AR 103033) and 12 cm3 (0,7 CU.In) flow (AR103035)... And, I soo that there exist an other type, more exactly 40 cm3/min. flow.....(AR39695, AR90459, AR97872)..
I supose the pump with 23CM2/min. would be good choose for this tractor, but I am not surre... Please, give me an advice....
Thanks, Benedek J.
Tx Jim
New Member
What type hyd diagnostics has been performed to determine your tractor needs another hyd pump? .7 cu inch pump has 4 pistons while 1.4 cu in has 8 pistons . Larger 40 cm3 is different body style so would require different fittings/supply tubes
historyan1975
Silver Member
Hi, TxJim... The problem is that - the tractor hydraulic does not lift, in the backside... Soo, it does not have enough oil pressure. This is one of my friends tractor, my own is JD 1020.
He replaced all of the filters, changed the hyd oil with JD HyGuard, changed the little pump in the crankcase... and does still not lift... He measured the oil pressure - it was only arround 100 bars, instead off 170 bar, as it has to be according to the descriptions---- He tried an other, used pump and worked... What other problem could have?
According to your opinion, the AR103033 or AR 103036 pump would be good? It does not wors to be fixed the old one...
All this pumps have 8 pistons?
Sincerelly,
Benedek J.
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Tx Jim
New Member
historyan1975
Silver Member
Hi,
The suction screen was checked and cleaned, the relief valve not yet, but they will verify it...
I found something new: ex. in morning, in cold, when the engine, the tractor body is cold - the lifting works perfectly... But, when it gets warmer, the lifting is weakens and finally, does not work at all... Ex. he was ploughing and he had to leave the tractor on field until it is not cold again and starts to lift again... AND, it did all these things with the other, used pump... it was ther same problem - in cold OK, when it got warmer, did not work. I mention - the servodirection works also related to the temperature.
Tx Jim
New Member
With hyd oil warm, engine operating 3 pt raised or 3pt control lever to the rear look into open hyd filler hole for moving oil. Moving oil indicates faulty 3 pt control valve seals. Internal hyd leaks causes hyd to heat lowering it's viscosity & lowers amount of oil available for frt pump therefore causes frt pump cavitation.
historyan1975
Silver Member
Thanks,
As I see, we have a multiple type of problems. What should be do?! Where do I find this control valve - to replace seals?
I checked on a few diagrams, but I could not to identify it...
Probably that the oil pump is not guilty for the problems, should we forget for now the pump problems__?!
Before - we replace the control valve seals?!
Thanks, Benedek J.
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Zebrafive
Super Member
Per TxJim: If you see oil spraying, looking in fill cap of the rockshaft housing, you have leaking rockshaft (3pt) valve seals. You have to remove the rockshaft housing to access the rockshaft cylinder/valve assembly.
I would check/repair this before changing the front pump.
I would check/repair this before changing the front pump.
Tx Jim
New Member
Ditto what Zebrafive stated. Repair internal hyd leak then proceed with more hyd diagnostics. Hyd internal leaks are contributing to poor frt hyd pump performance
historyan1975
Silver Member
historyan1975
Silver Member
O.K., I understand... Maybe -the big piston sealing are used (AR33105)? Or, we have to replace all seals on the piston and at valves.........?! DOES exist any repair kit for the valves? If not, what should be replaced from those little pieces from the valve diagramm? Only the O-rings_?
Tx Jim
New Member
Rockshaft control valve seals/gasket kit part # is AL57974 & piston seals are part # AL33105
If memory severs me, this is what our Hydraulic Relief Valve looked like after we pulled it. Notice the O ring on the left was shot and in pieces. Cheap fix with an assorted O ring kit, although I've found it is better in the long run to order the real thing from John Deere--they last longer and aren't very expensive. It may also be called the Filter Bypass Valve-- can't remember, did a lot of valves on this tractor.
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You should check out this guy. This video is about the Filter Bypass Valve on a 1640, but the principle remains the same for all these valves that are accessible from outside the tractor without taking the top off. In other words, do the cheap stuff first. It was worth watching just to get that hint about making sure the split in the split pin faces away from anything that is going to bang against it.
Btw--he is also has extensive videos about a 2030 he has been working on. Well worth the time.
Btw--he is also has extensive videos about a 2030 he has been working on. Well worth the time.
Here is another that you may or may not find helpful: the Flow Control Valve, or Pressure Control Valve, located under the right footrest, which you have to remove for easy access and also drain your hydraulic oil. This was an sob to get that nib off, and I had to eventually remove the whole thing. Notice once I got the nib off and the valve out, the O ring that was in pieces at lower middle 2nd pic. Also, where the pipe cleaner was going in to clean the port--that has an O ring that you place there after you get the whole thing cleaned up and are going to reattach to the tractor. Make sure you put a dab of grease on that spot to hold the O ring in place. Finally, the nib on the tractor which is helpful to remove and clean up, takes two new O rings to make a nice tight fit when you put the unit back on. Your configuration may not be the same but the principle is. My guess is that Tx Jim is right, you need to pull the Rockshaft, but doing these valves does not go astray.
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