JD 1530 Hydraulics quit after running for few minutes

Hi, I have a JD 1530 tractor that the hydraulics will quit after running for about 5 minutes or so. Before starting the tractor I pulled the top plug from the front hydraulic reservoir that sits above the front pump, it was completely full of oil. I drove the tractor running a rear PTO mower for 3-5 minutes then lost hyd pressure, making the PTO shut off, loader circuit not work, and power steering intermittent. At this point the front hyd tank was empty. If the tractor sits for a while (no set time I can figure out, 5 min or overnight) the front tank will fill back up, at which point I have good hyd flow again until the tank runs empty in about 5 minutes.

I've disconnected the loader SCV and capped the lines to eliminate a valve failure, same result. Looking in the rear filler hole with 3 pt up, I don't see any oil spraying. I can see the oil slowly circulating in the rear end, but no spraying, so I think this is normal.

I have read about steel lines inside the rear end that could be leaking, to check this do I need to remove the shifter cover from the top of the transmission and look for leaks? I'll have to order new gaskets I assume to do this, is it a good next step to take?

What else should I be checking that would cause the front reservoir to drain within a few minutes of running?

I found a related post at the link below, but didn't find a reply what the problem was.
http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=jd&th=489157

Thank you in advance for the help!

How's the oil level in the rear end on the dipstick ?

If your filter is getting clogged up with fines from brake parts it will run and then quit like you say and then work again after it sits and the metal settles back down. Take the oil filter out and look for metal filings.

Thanks for the quick reply Mike! Oil level is full on the dipstick. I have changed oil and filters, and cleaned screens, didn't find much on the screens and with new oil and filters problem persists. Other ideas?

I guess hook up a gauge and see how the charge pump pressure acts as the hyd. functions die.
I'm betting a JD service manual has a trouble shooting flow chart in it. If you don't have one it sounds like this project might require one.

Sounds like a high pressure leak to the sump.
It looks like you have researched this a bit and have started doing some testing, good for you. A couple of thoughts; Does your front pump have a destroking screw? If it does turn it "in" and run the tractor for a few minutes as you have done (you will not have any high pressure hyd. functions) but your pto should continue to operate. If your front tank remains full at this time you are reasonably sure that your low pressure circuit is OK.
I am still leaning toward a rockshaft valve leak as you have eliminated your loader and scv from the scenario. (they can be hard to see) A lube gauge and a destroking screw would really help here.
As far as the screen it wouldn't be a bad thing to check but usually once they are full they stay full

Hi
I will tell you right off the bat you need a genuine JD shop manual, for this tractor or A very good JD service tech to try diagnose this. I had
problems similar to this with an 1830. I started off trouble shooting with an I&t manual, Things didn't make sense so I got A genuine JD book. The
hyd test pages in the JD book were 3 times as thick as the whole I&T book. There are a whole lot of flows and pressures to check in sequence. Then
fix problems as you find them.
From what I found with this customers tractor there was Major problems with the trans pump, and other damaged components due to brake filings going
through the system. there are quite a few "O" ring seals in there as well It could be any of them leaking to.
You can't guess your problem, as you will end up spending money and chasing your tail. Parts for those tractors are expensive here in Canada. The
customer decided it was time to trade this one off as it was getting on in hours and had other issues, so I never did get to fix it in the end.
I really hope you haven't just bought this tractor as you might be finding out why the last guy got rid of it, or finding out why you should sell
it if you've had it a while L.O.L
Regards Robert

Not any more $$$ than any other tractor , any other place .

Great ideas guys, really appreciate the help. I did install the destroking valve on the front pump, so I will try to start with the front tank full and run the tractor with PTO engaged and destroking valve
turned in, and see if it still drains and if the rear PTO continues to run. I've struggled using the destroking valve since I installed it, when I turn it in then back out it seems to pinch the o-ring in
the valve and then it starts leaking right around the T handle and I have to put a new o-ring in it, anyone else see this problem?

Tech 7, if the PTO runs for a long time with the front pump destroked, does that tell me the rear charge pump is good? Or is the pressure gauge the only way to know for sure?

I do have the JD shop manual which I have walked through what I could without a pressure gauge, I think I have located a gauge I can use so testing some pressures is my next step. Hopefully the test kit I
use has the right connections to hook up to the tractor, the shop manual talks about the John Deere fitting number to use so I'm hoping it is a fitting I have available.

One last thought, don't known if it's coincidence or not but the steering column was leaking so I removed it and replaced the bottom gasket, as well as replacing all of the O-rings in the column as it went
back in. I think my dad ran it a while after that repair before the hydraulics quit but is there any way I could have pinched an O-ring or blocked a fluid port during that repair that would cause the
problem I am seeing with the front tank running out of oil?

(quoted from post at 21:59:35 09/28/15)

One last thought, don't known if it's coincidence or not but the steering column was leaking so I removed it and replaced the bottom gasket, as well as replacing all of the O-rings in the column as it went
back in. I think my dad ran it a while after that repair before the hydraulics quit but is there any way I could have pinched an O-ring or blocked a fluid port during that repair that would cause the
problem I am seeing with the front tank running out of oil?

Click to expand...

What type pto(hyd ind[lever between gear shift handles] or continuous[dual stage clutch])? To check for steering valve internal leakage disconnect steering supply line & cap rear supply line where steering line was attached then operate tractor.

PTO is hyd independent, yellow lever right in front of gear shift handles. Is the steering supply line the small steel line that connects at the lower right side of the steering column?

(quoted from post at 06:42:30 09/29/15) PTO is hyd independent, yellow lever right in front of gear shift handles. Is the steering supply line the small steel line that connects at the lower right side of the steering column?

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YES on steering line. Have you tried testing hyd's with pto both on & off?

I finally had a chance to get a pressure gauge on this tractor and do some more diagnostics. The JD tech manual had me connect the gauge to a port on the right front of the transmission housing, checking for high pressure from the front pump. At first I had good standby pressure (around 2150 psi I think), ran the loader and PTO for a while and after few minutes hyd functions started failing, at which time my pressure started falling off on my gauge. Also when I had good pressure I could destroke the front pump and see the gauge pressure drop to zero. Makes sense that the front pump can't hold pressure when it is starved for oil.

When I lose hyd functions, the hyd independent PTO also stops running. Since this runs off the rear pump, this tells me the charge pump in the transmission is either going out or not able to pull enough oil, is that accurate?

The oil level on the dipstick is full when I check it, so where is the oil going? I believe the trans pump is a gear pump, and I don't understand how this type of pump could work for a while then quit so I'm leaning towards an oil supply problem. The JD tech manual doesn't show any pressure tests on the rear pump, it only shows flow tests and I don't have that test equipment.

I looked again through the rear fill hole with tractor running and 3 pt completely raised. I still don't see any oil spraying, but I do see oil circulating and some bubbles, almost foam, moving on top of the oil. Is this still an indication of rockshaft seal leaking? If so would that explain my symptoms?

I'm about ready to go ahead and split the tractor as I believe the problem is either rear pump or an oil leak in the transmission housing, and would like some advice on what to look for once I get into it. Thanks again for all the help.

How are loader hyd's connected to tractor & with what type valve(scv or ind valve)? Before you split tractor you need to perform some serious DIAGNOSTIC's on hyd system.

Congratulations on actually thinking and trouble shooting. Instead of tearing everything apart and guessing.
The top cover of the transmission should lift off and allow a look inside with the engine running. Odds are that foam is from a damaged transmission line or fitting. A blown pto clutch or brake seal is possible .

(quoted from post at 12:30:20 10/22/15)
Congratulations on actually thinking and trouble shooting. Instead of tearing everything apart and guessing.
The top cover of the transmission should lift off and allow a look inside with the engine running. Odds are that foam is from a damaged transmission line or fitting. A blown pto clutch or brake seal is possible .

Click to expand...

b&d
Be sure and be wearing a ""rain suit"" when you remove the trans shift cover on a tractor with hyd ind pto as you'll need it when you fire up engine with shift cover off if trans pump is operating correctly and putting out 150+ psi.
Jim

bheston
How long since hyd filter was changed & sump screen checked?????????????

(quoted from post at 11:37:30 10/22/15)
bheston
How long since hyd filter was changed & sump screen checked?????????????

Click to expand...

I have isolated the loader circuit and capped the lines, and tested to make sure the closed center valve isn't leaking through, with it completely disconnected no change in behavior.

Tractor has probably only run a couple hours since filter was replaced and screens were checked, and when those were pulled the first time the screen was very clean.

Check to be sure hyd filter relief valve is seating properly.

I don't have my book in front of me, but I think I remember taking the hyd filter relief valve out on the right side of the rockshaft housing, if I'm thinking of the right one, it's been a while since I looked at that. Anything I would be looking for other than broken spring or other parts? I could sure check this again, before pulling the shift cover off and inspecting.

Hyd filter relief valve is other objects on RH side of trans case in photo other than screen(parts key 15)

I made it back to the tractor last weekend. I first pulled the pressure relief valve and inspected, clean and appeared to function smoothly, so I went to the transmission shift cover next. Pulled the cover, from there you can see the top of 4 internal hydraulic lines. 3 of them had oil sitting in them, one I couldn't see the oil. Blew air threw it and could hear it coming out, leaking somewhere several inches down on that tube. So got right to it and split the tractor so I could get to this line. Found that on left hand shift linkage, a piece of metal had broken from the shift linkage where the shift lever contacts the linkage that goes into the transmission, looking at the damage to the tube it appears this piece of metal that broke came in contact with the tube and put a hole in it. Got the tube removed and a replacement ordered along with some new gaskets. Great advice, appreciate the help troubleshooting this one so I could properly diagnose before splitting the tractor.

Next problem, is that shift linkage that broke. I'll try to post a picture with this reply, but the shift rod is still working as it is, but may have a hard time shifting into park in the future if the shift lever doesn't fully engage this part. The linkage goes back into the transmission, and I would have to access the transmission housing to replace the whole part. So, how hard is it to take the top off the transmission case and get to this shift linkage and replace it? Anything I need to watch out for?

Picture of broken shifter linkage below.

I'm glad you found your tractors hyd problem.

I seen several of the shift tabs welded back together. To replace shift rail one needs to remove RS housing as you stated then when shift rail is removed watch for loose detent balls & springs as rail is pulled from trans case.