Another JD 2155 Hydro Thread

[JoshB]

I have a 2155 that I was out running my rotary cutter with. As I was driving noticed the steering begin to get stiff if I slowed down. I then stopped and noticed I had no power steering anymore. Then when I went to raise the loader it actually lowered as though it lost whatever pressure it previously had. I checked the rock shaft (I think that is the right term for the 3 point lift arm?) and it also lowered instead of raised. Checked and there was NOT a hydraulic pressure indication illuminated on the cluster.

At that time I was out on some land I own with only a small bag of tools in my truck. I removed the hyd filter and sprayed it with parts cleaner until it was clear. I had just changed the filter completely only about 5 hours prior. I also removed and cleaned the sump screen which was a good bit dirty but not like I've seen some people post pictures of. Since I didn't have access to all new trans/hyd fluid (it was a Saturday and my local JD dealer was closed) I recycled the recovered fluid that drained out of the sump. By the way... It was very dirty.... Almost black!

I put it all back together and there was no change at all. I read about checking the bypass valve but I'm not sure "how" to check it. Also, I have not yet performed a standby pressure test because I still have to order a set of gauges. One thing I did check is on the front pump I very slightly loosened one of the main lines coming off the pump and it immediately started leaking as though it's under pressure. I can also hear sort of a knocking sound coming from it (not sure if that's normal... First tractor and have only put about 10 hours on it personally). I put a very long screwdriver against it and the handle to my ear and it's definitely knocking from the pump. Again, I just don't know if that's normal. I do believe that the pump is being driven by the tranny output shaft though.

I now have another new filter and 7 gallons of new fluid. I just don't want to drain it etc yet until I feel like I have some sense of direction, then have to do it again for another reason.

It's weird because it was very sudden and affected everything, with no obvious noises or anything.

Possible that the filter is still the culprit?

How do I "inspect" the bypass valve?

I also looked into the filler port of the tranny and do not see any sort of spraying onto anything. Should there be, or should there not be?

Obviously the fluid is very dirty but would that kill the filter in just a few hours?

Any help would be greatly appreciated!!

 

[jd110]

Lots of possibilities here. Usually knocking noise in front pump is either a loose pump coupler or lack of enough oil being supplied from transmission pump. What kind of "dirt" was in the sump screen? If oil is very dirty, I suspect you might have failed brake contaminating it. Can you post pictures of the debris removed from the screen? Which line did you loosen on the pump? If you remove the filter bypass valve, look for any debris holding it open. If not sure, include some pictures of it and I can help to determine if anything is wrong with it.

 

[JoshB]

JD110, First- Thank you for the reply!

I can only hear the pump knocking if I get right up to it. That's why I'm not sure if it's a noise that's always been there. The noise is internal to the pump.

The sump screen had mostly gooey sludge like it hadn't been cleaned in a good while. There were a few pieces of metal flashings as well. I can't post pictures of that one because I cleaned it all off last week when it all started and had high hopes that cleaning it would resolve the issue. I had not even found this forum until after that day.

The line I loosened is on the right side of the front pump. It goes from the bottom right, on up into a flexible hose. I went for that one because when I first bought the tractor I noticed a leak there and fixed it by simply sight ending up the hose clamp that's there. I can take pictures of it if need be. As soon as it was just slightly loosened, the fluid started to come out. It seemed like it was at least going to flow as much as it did when it was leaking on me before.

On the filter bypass valve, I pulled the plug (item #1 in the pic below), and a very slight bit of fluid came out. I didn't go beyond that though. Item #2 (threaded nipple) is pretty large and I didn't have a socket that size with me at the time. Both the threaded nipple and the plug were fully seated, so I'm not sure what an open or closed valve should look like. Perhaps it will be more obvious once I remove it?

Once I get it out I will take pictures of everything from this point on.

Any advice on the previous question about the filler port and no oil visibly spraying on the gears in there? Is that a good or a bad thing?

As a side note - Although I need to drain and replace the fluid, the dipstick does show that it's within the proper level.

 

[Zebrafive]

No spraying is good. If you see spraying you have an leak of the rockshaft control valve. Something is making the oil black, maybe brakes like jd110 said. When I've drained the oil from my 2030 is honey color, a change from almost clear when installed.

 

[JoshB]

Thank you.

Regarding the fluid color, I have no idea how old that fluid is but I do have new Hy-Gard to service it with.

 

[DT86]

I had a 2355 and had similar hydraulic problems as you. The dark mess and metal specks in the filter ended up being park brake pad and the rivets that hold them.

Dad was always bad about taking off with the brake on, but a dragging park brake could do the same thing.

Anyway, despite being flushed it ended up eating several hydraulic components and replacing the brakes was no small task either.

I wouldn't wish the experience on anyone.

 

[JoshB]

I'll have to look into the potential brake issue. But would dark fluid from the brake cause the system to suddenly lose pressure? I'm really hoping the bypass valve is stuck open. Would really make my day!

 

[DT86]

In my case the metal rivets from the brakes caused the problems.

I was mowing along and suddenly could only steer left, then not at all. It has been several years and I don't remember the details anymore.

 

[JoshB]

Here is a picture of the bypass valve. It was in the closed position upon removal.



Also - Here is the line that flows if I loosen the hose clamp. I was incorrect in my OP when I said it comes straight off the front pump, it actually comes from the rear then along the lower right hand side. Then up and into a reservoir that sits above the pump, then over to the left, then into the top of the pump.

It looks like the cap to the standby pressure test port??









I reinstalled the bypass valve and changed the filter. No change.

One thing I did notice is that around center, the steering is very easy to move. Not just because there isn't much load at center, but it actually feels powered. As soon as I get much off center though, I can feel the power steering has no hyd support. Also, it feels like it's cycling in the wheel. "Pulsing" if that makes sense? The loader doesn't budge and the 3pt looks like it wants to lift but has no power to raise the bush hog that's attached to it.

 

[JoshB]

Update - I fully disconnected the bush hog and the 3pt lift arms in the back will raise up albeit extremely slowly, as long as there isn't any significant weight on them.

I guess the next step is to verify the standby pressure?

Anyone know of an inexpensive test set online?