4430 Hydraulics Slow After Heating Up Solved

Letting everyone know that in the case of my baler tailgate raising slowly after warming up, it turned out to be my front hydraulic pump. Now to get all to Tim S. to see if rebuild or replace. Thanks for all the info!
 

What diagnostics did you perform to determine frt hyd pump is faulty? Many closed center hyd pumps have been replaced/repaired to determine that the pump wasn't at fault.
 
Ummmm i cannot see that a front pump issue would cause the symptoms you describe. I agree with Tx Jim. If you change
out your pump I would bet your problem will still exist.
I would think that the problem is a leaking SCV. 2 minutes with a 5000 lb gauge would tell a lot
 
I'm not sure you understood the other poster's questions / feedback?

How did you determine that the main(front) hyd. pump needs to be repaired / replaced?

It would be a shame for you to send it all the way to Tim only for him to tell you that it wasn't causing your problem.

Unless, of course, you've troubleshot the circuit properly........

(quoted from post at 18:40:24 07/16/18) I'm curious also. I plan on sending this pump to Tim S. To have him bench test. I'll let you know the results.
 
The problem with this tractor was not oil heating up. It would not raise and lower my 567 baler tailgate property after the tractor, and oil, warmed up. I checked pressure at scv's when I first noticed this and it was around 17-1800. I raised pressure to about 2200 and tried it again. Still had same problem. I tried checking this and that for something warming up to no avail. I carried to my local mechanics who told me tractor had 3000# pressure when they checked place other than scv's. Was told tractor would start with good pressure at scv's but drop after warming up. I took a pump off another tractor and put on this one over the weekend. Everything seemed to work as it should. I do not know what all was tested to determine but these guys have been working on John Deere's a long time. I still wanted to send pump to Tim to verify instead of letting those mechanics start rebuilding pump.
 

From your description of hyd pressure being higher than 2250 psi when checked at location other than scv I'd suspect there's a problem with pressure control valve(key 6) not letting full pump pressure/flow make it to scv.

mvphoto19925.png
 
A sticky stroke control valve or one with a bad seat can cause this...I will know when it gets on the test stand...
 
Fair enough.

If the slow cycle times on the baler gate was cured by replacing the pump with a known good unit that's definitive enough, although quite labor intensive.

Still have to wonder about the varying pressures that were taken throughout the system. As per TxJim, there could still be existing issues.......

(quoted from post at 04:24:02 07/17/18) The problem with this tractor was not oil heating up. It would not raise and lower my 567 baler tailgate property after the tractor, and oil, warmed up. I checked pressure at scv's when I first noticed this and it was around 17-1800. I raised pressure to about 2200 and tried it again. Still had same problem. I tried checking this and that for something warming up to no avail. I carried to my local mechanics who told me tractor had 3000# pressure when they checked place other than scv's. Was told tractor would start with good pressure at scv's but drop after warming up. I took a pump off another tractor and put on this one over the weekend. Everything seemed to work as it should. I do not know what all was tested to determine but these guys have been working on John Deere's a long time. I still wanted to send pump to Tim to verify instead of letting those mechanics start rebuilding pump.
 

Going through the same type of problem with my 4430 right now. One of the most frustrating mechanical problems you can come up against. I wouldn't mind the work, or even the expense to some degree if I could just find out definitively what the problem is and fix it without throwing a bunch of unnecessary parts at it first.
 
I will let you know about the results when I get the pump on the stand,,I will have uninpeaded charge flow and no hi pressure leakage caused by various valves...the bad part is paying for the ride here..
a273901.jpg
 
(quoted from post at 12:32:41 07/18/18) I will let you know about the results when I get the pump on the stand,,I will have uninpeaded charge flow and no hi pressure leakage caused by various valves...the bad part is paying for the ride here..
a273901.jpg

Still an excellent value for the dollar . That hydraulic test rig is better than most of the calibration lab equipment that I have used in a nuclear power plant .
 
Tim,

What are you using to drive the pump & what are you using for a charge pump?

I don't believe I've ever noticed those details in your test stand pictures......


(quoted from post at 09:32:41 07/18/18)I will have uninpeaded charge flow and no hi pressure leakage caused by various valves...
 
I run it with a 30HP motor spinning a shaft at 2100 RPM.. a pump on the one end powers the test bench,, when I want to test a pump I disconnect the pump that stays with the bench shift a diverted valve to send the charge oil to the pump being tested, the end of an old pump shaft is plugged into the jack shaft and I use a standard splined coupling to connect the pumps,,a charge pump is mounted onto the end of the 30hp motor,,it's kind of a Hillbilly set up,,but it works well...
a274004.jpg

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a274006.jpg
 
Looks like a good set-up to me. Completely purpose built for testing Deere components properly so nothing Hillbilly at all about it IMO....

I highly doubt that most dealerships have anything close to that for testing the main hyd. components.....

(quoted from post at 08:23:54 07/19/18) I run it with a 30HP motor spinning a shaft at 2100 RPM.. a pump on the one end powers the test bench,, when I want to test a pump I disconnect the pump that stays with the bench shift a diverted valve to send the charge oil to the pump being tested, the end of an old pump shaft is plugged into the jack shaft and I use a standard splined coupling to connect the pumps,,a charge pump is mounted onto the end of the 30hp motor,,it's kind of a Hillbilly set up,,but it works
 
Letting everyone know the outcome on this issue.

Per Tim...The crank case outlet valve was stuck on your pump,,it ran fair when I put it on the stand first thing,,but acted a little erratic... I pulled the stroke valve and it was good,,then I pulled the outlet valve to find it stuck tight,,,,ran it on the stand again and it ran a lot smoother,,so I am not sure if this was all your problem,, but we know this part is good,,

I used another pump in the meantime and my baler tensioning arm would work as designed when lowering tailgate so the belts would not pinch. Tailgate also raised faster.
 

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