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Well that is depressing. It does confirm your observation of fluid flowing out of the gear without any steering input as being the problem. It also confirms that a cylinder (leaking or not) would not cause the symptoms you are having.
Looking at my own 284 more closely I was wrong about the role of the priority valve. It does not give priority to the steering over the loader. The loader is in the circuit before the p-valve. What the p-valve does it give priority to the steering over the 3 point. The p-valve plumbing does not change with or without a loader.
Since the p-valve sends fluid to either the steering gear or the 3-point I don’t see how it could possibly effect the steering gear output.
Unfortunately that leaves only one part left, the steering gear itself.
The old one is a little blurry. Does it use the same type of seal as the new one?
Please post a picture of the fittings as they used a couple of different styles on the loaders.
Measure the inside of the threads on the cylinders and the outside of the threads on the fittings. Post the measurements and we can figure out what you have. Then we can look for suitable adapters.
The 20mm x1.5 jam nut fit perfectly on the steel line, which as an o-ring on the end of it’s face. So, now I need to find a 20mm cap that has a flat face on the inside, or I need to find a full size 20mm nut that I can weld a plug with a flat face inside it.
That is for a DIN fitting and probably won’t work on a face seal connector. The only place I have DIN fittings on my 284 are on the Z-20 loader. The tractor and backhoe all seem to be either O-Ring face seal or BOSS seal (sealing washer with straight threads). DIN is a different animal completely.
Maybe you could use a metal “slug” and another o-ring. By slug I mean a metal disk like a knockout from an electrical box or maybe even a coin.
Put the slug between the two o-rings and re-assemble the joint. That would provide a makeshift plug so that you could do the testing on the cylinder. Just don’t forget to take it out before starting the engine!
You should be able to find the appropriate cap online somewhere. Your idea of welding flat metal to a nut with an o-ring for a seal sounds like a good solution too.
Another option is to use a 9022FC adapter to convert it to a 1/2″ JIC fitting. JIC caps are easy to find. Take a look at adaptall.com for all kinds of goodies along this line.
Neither the tractor nor engine parts books for my Jinma 284 show the pump to engine connection details. It is my understanding that the pump has a tang that protrudes from the pump. This tang engages a slot in the drive gear of the engine. I have never had my pump off so I am not sure what it looks like on the inside.
Do you know what engine you have? That might help to find a parts diagram of how things are supposed to be.
Short of that, could you post a picture or two of the pump and pump mounting point taken with the pump removed so we can see what is inside the housing?
Try an equipment dealer. Caterpillar has quite an assortment of things if not in stock at least available. Bobcat or Kubota dealers might have metric caps and plugs too.
Double click the image in previous post to open up the whole chart.
There are two styles of o-ring seals for straight thread connections. One is o-ring face where the seal is on the end of the tube and the other is sometimes called a BOSS fitting where the seal is either an o-ring held captive in a washer that sits at the base of the threads. Sometimes these washers have the rubber seal molded onto the washer so they are one piece.
If you can get a plug or cap to seal you can fill one side of the cylinder and plug the port. Then apply pressure on the cylinder rod and check for leakage at the open port. Keep in mind that a cylinder that leaks in one part of the travel may seal in other places.
You are on the right path to figuring out the problem before spraying parts (and $$) in hopes of guessing right.
Many types of equipment these days are controlled by joysticks so you are not that far off. With a little practice it becomes second nature.
As for your hydraulic fittings/adapters. You can’t measure the threads (or the hole) and directly get the size. Discount Hydraulic has a pretty good guide posted on their web site. Newline also has one that is downloadable in PDF format. I have both of these in my shop for figuring out fittings on my Jinma. They do use a conglomeration of styles and sizes!
If you can’t find them let me know and I will post them on my web site so you can see them. With a caliper and some thread gauges you can figure it out fairly well. Finding the adapters is more challenging. Sometimes you have to go to something else first to get where you really want to go. I am slowly converting things to JIC so that I can have hoses made locally.
I certainly wouldn’t want to take the steering gear apart until I had a new one installed and was sure the old one was bad. Then when it didn’t matter what happened to it, I would take it apart just to see if I could figure out how it worked.
I think when the cylinder bottoms out the gearbox becomes fully pressurized on the side you are turning to. What makes it seem like it won’t turn any more is that the oil has no place to go so it feels stopped. While you are turning, the oil is moving and you don’t feel that resistance.
Let me know about the measuring guides. It will take me a little while to move the files and build the links on the web page. I have some files about the 284 posted already but have not had time to put everything I have collected on the web page yet.
The priority valve is there to make sure the steering always has enough pressure to operate. If you are moving the loader (or raising the 3 point) and turn the steering wheel while doing so, it is supposed to give priority to the steering and any left over pump output can go elsewhere. The reason is that steering is more important than lifting.
My loader valve (not Jinma) has a pressure relief valve but there must be another one in the system somewhere because when I remove the loader the bypass still kicks in when the 3 point or steering hits the limits. It might well be part of the priority valve. I wouldn’t want to try bypassing that because it may very well dead head the pump if there is no place for the fluid to go.
It sure sounds like your gearbox is leaking internally. That would explain the fluid leaking into the glove and would explain why the steering wheel keeps turning even when the tires are at the stop. An internal cylinder leak could explain the steering wheel but I don’t think it could cause the fluid in the glove.
If the priority valve was malfunctioning it could cause low pressure to the steering which would show up as no power steering. I think you have eliminated the priority valve. To test this disconnect the loader and plug the two tractor lines into each other. You will still be able to test the steering and use the 3 point.
The cylinder likely has metric BOSS fittings. A hydraulic shop should be able to connect to it. If not, you can buy adapters online. Try Discount Hydraulics or Clear Water Hydraulics. They should be able to adapt it to JIC. They also have handy measuring guides to help you figure out what type and size of connectors you need.
