She's leaking...

[Conservative1]

Bushhogging today, I noticed some fluid was on the left front tire, inside. It looked like oil, which is never a good sign. It's bone dry out here, so it can't be water from the ground. I got her back to the house, in the shade, and found the source. I assume this is the hydraulic pump? It has four bolts on the bottom of it where the line connects to the pump (You can get a good idea by looking at the connection of the line just to the right of the leaking line- they look the same). I assume I might can tighten those bolts up and make it stop leaking. But, given my propensity to really screw up an easy job, and Murphy's love of living here on my place, I wanted to check with y'all first.
JD790, 285 hours, never been rolled, flipped, or wrecked, but she's done just about everything else a tractor can do. Pic is attached.

Is this a simple fix? Could the pump be going bad? If it's just a matter of "Tighten the line", then heck yeah. My fear is, it's something worse.

 

[RoyJackson]

The line coming in at the bottom is the pressure line.

By the way, you've got the side cover off and you may as well leave it off while doing this.

First, clean the pump off so you can give it a good visual. Start the engine and observe for any leakage or spraying oil. I'd suggest letting the tractor run long enough to ensure it's at operating temperature. You could run it down the drive and raise and lower the FEL a couple times to put some load on the pump. Also, use the power steering.

Then park...leave the engine at idle and examine the pump for leakage. That's high pressure, so don't use your hands (there's a number in the tractor's manual to call if you get fluid injected into your skin. Take the manual with you to the hospital.). If you cannot see fluid oozing or a spray, use a piece of paper around the pump. If the paper gets wet with oil, you've found the leak.

Shut the engine down and relieve any pressure using the joy stick

I suspect the line has vibrated loose. Use a proper fitting wrench and tighten it, if necessary. Then repeat the above.

If tightening the line doesn't fix it, it may be a crack in the line (probably a flare cracked). That would require replacing the line.

I doubt if you lost much fluid, but I do suggest you check the hydraulic fluid level.

 

[MJPetersen]

It could be a crack in the line or where the line attaches to the clock, as Roy stated, but more likely it is the o-ring. The block that bolts to the bottom side of the pump with 4 small bolts and that has the line going into it uses an o-ring for a seal. These are normally very good seals and do not create any problems. (Notice the other section on your pump is bone dry.) It is an inexpensive fix, but very messy.

Try tightening the bolts a little first. If that does not do it, then you will have to take the bolts out, the line will probably drop down a little, you do not want to bend it, but it will flex enough to get to the o-ring (you may have to remove a clamp), replace the o-ring with the correct size (diameter and thickness), and connect it all back up. Make sure everything is CLEAN!!

For really high pressure systems they use a metal-backed o-ring, but you most likely have the simple black rubber o-ring. The old o-ring will probably have an area that looks a little rough, but I have seen then were they are half eaten away with the high pressure oil eroding the o-ring. Please do not use fingers to find leaks. High pressure oil can penetrate skin. However, I believe yours is not to that point yet--it is at the seeper stage. Oil under pressure when lifting a load is starting to seep past the o-ring. It probably does not leak at all except under working pressure.

You will loose some oil but that should get you back in the dirt.

In my opinion that is probably your problem.

Mike

 

[RoyJackson]

MJ is right, that's an O-Ring (PN CH11562 it looks like) with 4 bolts on the flange of the pressure line (rather then a flared line).
The O-Ring is Item 2, the line itself is Item 3 in the attached picture (which came from the Deere Parts website).

I hope just tightening the flange bolts works. That line appears to be a welded or brazed assembly and is probably rather costly (as well as a PITA to install).

 

[Conservative1]

Thanks to both of you, great info. I'm headed out to work in a few minutes, but will try to tighten those bolts this evening if I get in early enough. I'll post the outcome when I get a look at it.

 

[sandman2234]

If the line is leaking and not the o-ring, consider having it welded back. A truckdriver here had a Kubota with a cracked line and when I saw him with the orange line, I asked what it fit. I suggested he take it to a hydraulic shop here and let them weld it back. I had seen that shop weld up a similar line and knew they could/would do it. He told me the next day they did it for $20 and he had it back on and running that night.
Check into the welding skills of whoever you have do it if it is a cracked weld to make sure they know what they are doing. Otherwise they could easily damage the line, causing you some long waits while your part is located and shipped.
David from jax

 

[zzvyb6]

Are there 2 hyd. pumps on this tractor? 790 system diagrahm suggests there is a hydraulic pump and a power steering pump piggybacked. The hydraulic system has a seal (ET14364) which is on the front of the hydraulic pump where the power steering pump goes on.

 

[MJPetersen]

If the line is cracked where it goes into the block or the joint is leaking at the line/block then you can also braze it with as great a certainty as welding. I have brazed such things many times and also lines that have cracked or worn through. The high strength brazing is easy and very durable.

Mike

 

[RoyJackson]

If the line is cracked where it goes into the block or the joint is leaking at the line/block then you can also braze it with as great a certainty as welding. I have brazed such things many times and also lines that have cracked or worn through. The high strength brazing is easy and very durable.

Mike

Yep...just make sure it's well cleaned first.

 

[RoyJackson]

Are there 2 hyd. pumps on this tractor? 790 system diagrahm suggests there is a hydraulic pump and a power steering pump piggybacked. The hydraulic system has a seal (ET14364) which is on the front of the hydraulic pump where the power steering pump goes on.

The Deere parts website show 2 different pumps and PN's for those pumps.
PN AM876753 is the PS pump PN, AM876750 is the system pump PN.

 

[diyDave]

2 things, after you clean up the pump and line. 1. Loosen all clamps that hold that line to the motor, loader,etc. 2. Loosen the other end of the line, all of this may let you just pry the line loose enough to replace the o-ring , if that is the problem.

 

[Conservative1]

Just shoot me and get it over with...

It took three weeks for me to get to the dealer's parts counter. (Full time job, their hours are the same as mine) Got the O-ring, and today, got on it. The old seal looks pretty good- it wasn't as worn out or chewed up as I thought it would be. The line looks good. I stuck the new one in, and bolted her back in. Everything was going fine. Welp, got down to the end, got everything back in place, and gave one last little tug for good luck on each bolt. Yep, you guessed it, I broke one.

A 62 cent problem is costing me a LOT of frustration, and a little more cash, right now.

CRAP.

 

[Soundguy]

Yep.. remember.. when you snug down bolts and nuts to only tighten right up to the point before they break (wink).

I feel for you.. a flat tire a while back cost me a days work.. after I removed the tire ( not super easy on a large tractor), got it to town.. got it plugged, and then hom.. I went and twisted of a stud while mounting it. Another trip to town. this time on the edge of town.. ).. by the time I got it all mounted.. my day was shot.. go figure.

Good luck on extracting that stud or bolt fragment. Hopefully it will come out with you looking at it. if it were me / my luck.. it will be major surgery and require drilling out etc.. etc..

Soundguy