Jinma 284 Steering Question

[DoctorZoidberg]

Hey guys,

I have a Jinma 284 (I believe a 2007) with a FEL. I have read quite a bit about the seals for the power steering hydraulics being a common problem for these tractors. My question is, does anyone know how I can test the steering without disconnecting everything? Is there some sort of "spec" for the steering that I can test? I'm thinking something like # of inches the wheels turn vs number of turns on the steering wheel or amount of force required to turn the steering wheel, etc.

The reason I ask is because the steering seems a bit difficult to me but its not so bad that I am sure there is a problem somewhere. It just seems like it could be a bit heavier than normal or require more wheel turn that i should but it could also be that it just how these tractors are! My father has a newer John Deere and it takes much more effort so that is really all I have to compare to. I would expect the Deere to certainly have nicer steering but just wondering if it should be that much of a difference or if it is just because mine has a FEL and his does not.

#Forgot to mention the tractor has turf tires on it currently.

Thanks in advance!

 

[cleat]

My Dong Feng can be steered with one finger easily with a bucket full of gravel. Hydro steering is real easy. Now precision on the road is another matter entirely...

 

[DoctorZoidberg]

Thanks for the info, I was suspecting a problem and that my steering was much heavier than it should have been. Well, no sooner did I post this question when I go outside tonight and the steering is pretty much gone now. Well, I guess I have my answer now! I am actually quite excited that the steering should be as you describe!

So now it looks like I either need to go the rebuild kit route or just bite the bullet and order a new one. Does anyone have any experience with rebuilding these cylinders and if so how easy is it to do and how well do they hold up? If I am just going to have to keep rebuilding it I would probably just rather buy new. Looks like a new one will run me around $240 though...

Thanks again!

 

[RonMar]

+1, my 284 is fingertip steering. Are you sure it is the cylinder? If it were the piston seal in the cylinder, it would still steer with 1 finger... It would just take more turns of the wheel to shift the wheels from full left to right. Or the wheel would turn but the front tires would not change direction as the fluid flows by the piston without building enough pressure/delivering enough force to move it.

First off, is your hydraulic fluid level correct? Low or aireated flow will cause erratic hydraulic operation, which includes steering. Does the loader and 3PH work OK?

The power in your power steering comes from the hydraulic pump via the diverter valve located down by your brake pedals. The purpose of the diverter is to divert flow to the steering when the rotaty vane pump at the bottom of the steering column demands it/sends fluid to-from the steering cylinder when the wheel is turned. If the diverter was stuck, you would have no power steering. You would however still have steering as long as there is fluid in the system, the vane pump at the base of the steering column will pump fluid to-from the steering cylinder and turn the wheels.

With the engine shut off, does your steering work? It will be hard as your arms are providing all the force to move the cylinder.

With the engine running, lift the 3PH and at the same time turn the wheel. The purpose of the diverter is to give the steering priority over the 3PH. Because of this the 3PH should slow/pause while the wheel is being turned. If it dosn't, the diverter isn't diverting...

 

[Affordable]

It sounds like the cylinder is bypassing internally, if you are mechanical the seal kit is not not hard to install getting the ones in the end cap can be the hardest part for most people. You have 3- options, 1- Buy the kit and install it yourself, 2- Buy the kit and have someone install it for you, 3- Buy a replacement cylinder.

We have the kits and the cylinders in stock

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[DoctorZoidberg]

Ron,

When I checked the loader and the 3 point hitch they both seemed to operate OK (hitch doesn't have any implement on it at the moment though so not much weight to lift). I'll double check the fluid level but I believe they should be alright.

A few weeks ago I flushed out the hydraulics and put new fluids in because I was not sure when the last time it had been changed was. I was hoping that might improve the steering but it seemed to have no effect for better or worse.

Right now, with the tires on the ground, the wheel turns pretty easily and there is no movement of the wheels at all. It is like this both with the engine on and off. I'll try your suggestion about raising the hitch and turning the wheels to see if it stutters at all.

When the steering WAS working it was a little heavy but mostly seemed to just require way too many revolutions of the steering wheel to get the wheel to turn.

I'll report back with what I find.

Thanks again!

 

[DoctorZoidberg]

Here's an update, I was able to check everything out again before going to work and here is what I found:

-I must not have had the front wheels all the way off the ground because this time I made sure to lift the wheels entirely off the ground and the wheels turn in both directions, seems to be a bit jerky though. With the wheels on the ground (not moving) they do not seem to move at all. While moving they apparently DO move it is just such a small amount per turn of the steering wheel that it looks like it isn't even moving. If you keep turning the wheel enough times it eventually does move the tires.

-I checked the hydraulic fluid level after that and it was a bit low but nothing drastic, I topped it off and tested everything again and it didn't seem to make a difference.

-I tried to move the wheel while lifting the hitch but did not see the hitch stutter at all while I was turning the wheels. This was a bit tough to test though as I do not have an implement on it at the moment so it raises quite quickly. Also, I assume without the weight I wouldn't notice much of a stutter at all while turning the wheel?

So I am assuming that rebuilding the cylinder is the cheapest/easiest thing to try first? If so, is there anything special I need to do prior to removing the cylinder to remove pressure from the lines?

Thanks!

 

[RonMar]

With that last information, I agree that the cylinder piston seal bypassing is the most likley. From your earlier descriptions I got the impresion it was working but hard to turn the wheel... Yes a bit of weight on the 3PH makes the divert function more obvious.

If it had the standard chinese motor oil in the hydraulics and you shifted to actual AW32 hydraulic fluid, this thinner fluid would most likley cause a leaking seal to leak worse.

The seal rebuild is not terribly difficult. Probably the hardest part is getting the rod end cap unscrewed as this requires you to cobble together a spanner of some sort to engage the pin holes in the end cap. You can use a cut up soda can and a hose clamp to compress the new(and well oiled) seal for a clean re-installation back into the cylinder

IF you provide the parts, and bring the cylinder to them clean, a local hydraulic shop can do the job in well under an hour(probably 10 minutes while you wait/watch)...

 

[DoctorZoidberg]

I am going to take the cylinder off and pull it apart to see what it is like on the inside and if I think I will be able to tackle the job.

Is there anything in particular I need to do before I unscrew the hoses from the cylinder to avoid fluid being sprayed everywhere? Since these are not quick disconnects how do you prevent them from leaking like crazy once disconnected, or are they not pressurized as long as the engine is off and therefor the pump is not on?

 

[Affordable]

You should only lose a little oil after you disconnect the lines, just use a oil drain pan.

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[RonMar]

+1, the lines shouldn't drain too much when disconnected. Also the cylinder is full of fluid which will come out when you push/pull on the rod end so have a bucket under the ports to push the fluid into once it is disconnected. It is probably best to get the rod end disconnected before you disconnect the hydraulic lines...

 

[DoctorZoidberg]

Well Ron, unfortunately I did not see your post before disconnecting and taking apart the cylinder, I managed to squirt oil all over myself and my garage when I pushed on the rod! Hindsight, of course it would have done that, oops!

So I did manage to get everything disconnected and the taken apart, I have a couple questions that hopefully having some pictures will help.

First, when I was taking the cylinder off the tractor, is there a way to do it without completely destroying the rubber cover? I got fed up holding it back and decided to just cut it off, of course that was before I realized a new one was $20! Either way I don't know if I could have gotten it off without cutting it.

Second, on the right hand side (if you're sitting on the tractor) should you be able to disconnect the section highlighted in red? No matter what I tried I could NOT get it off so I ended up taking the entire plate that it is connected to off. Even after it was disconnected and put in a vice I could not remove it, even hitting it with a hammer (using a board to protect the threads) it would not budge.



Next, in this piece it looks like there is a slot for an O-ring and there definitely was not one when I took it apart, I assume there is supposed to be one here?



Also, the rest of the seals seem like they may have been replaced at some point, they are blue gaskets that look relatively new, all the replacement kits I am seeing are blue were the original ones blue as well? I don't see any obvious signs of damage on any of the other seals, they actually all look quite good. Should I still go ahead and replace all the seals or just the one that I assume is missing?

Thanks again for all the help! I would never have attempted this without this message board!

 

[Affordable]

Where's the rod at ? What do the seals on the back part of the piston look like ??

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[DoctorZoidberg]

Here you go:

 

[Affordable]

Those seals look good, I do not think that is your problem, the 2- blue seals on the piston are normally what goes bad allowing the oil to bypass, so they would be deformed or broken yours are not

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[DoctorZoidberg]

OK, what about the groove inside the piston is that supposed to have an o-ring?

In this picture it looks like there is supposed to be one (or possibly 2??) inside, mine had nothing at all when I took it out.



If there is supposed to be one, do you know what size it is supposed to be? I should be able to find it locally hopefully if so.

Thanks!

 

[DoctorZoidberg]

So I am out looking at my tractor again was going to disconnect and clean the diverter valve to see if that solves the problem and for the life of me I can not find it. Everything I have read said it should be by my right foot when sitting on the tractor, is this correct?

I am not finding anything on my tractor that resembles any of the pictures I am seeing online of the diverter valve.

When I trace the hydraulic lines from the steering cylinder back I see it connect to hard lines, which then in turn connect to the base of the steering column.



From that, two other lines come out, one attaches to what looks like the hydraulic pump and one attaches to what looks like some sort of reservoir in front of the radiator. The reservoir then also connects back into the pump. The one it is connected to is the one on the left in the picture.



Is it possible that there are 2 separate pumps, one for the steering and one for the 3-point hitch and the loader? It looks like the 3-point hitch valve connects directly to a line that is connected to the valve for the bucket loader.

Is this correct or did someone seriously screw up the hydraulics when assembling the tractor? If it is correct, could it be that I just need to put some hydraulic fluid in that reservoir at the front of the tractor? It doesn't have a dipstick or anything, when I unscrew the cap I just see a screen in the cap for filtering whatever goes in there, similar to the one when you open the fuel tank.

Thanks!

 

[DoctorZoidberg]

Just a follow up, I found this thread and my hydraulics seem to be setup the same way:

http://www.tractorbynet.com/forums/chinese-tractors/116801-power-steering-pump-repair-kama-2.html

 

[Affordable]

You don't have a diverter valve because you have a separate pump for the steering,did you confirm you had fluid in the tank in front of your radiator( the tank next to your air breather)

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[DoctorZoidberg]

Any idea how full the tank should be? Unlike the other hydraulic tank in the rear it doesn't have a dipstick or anything. Should I just fill it up almost to the brim?

I'm going to try to put it back together and top off that tank and will report back.

Thanks again guys!