Jinma 254 Power Steering / hydraulic Q

[cjax]

Ok, bought a used (less than 80 hours) JM254 last weekend. Used it for about 2 hours, and it has done everything I need so far. Only problem is, the power steering is/was sluggish at best. I do a lot of turning, as I have an oddly shaped lot (though 20 acres) and a lot of hills.
About 1.5 hours into my work, I started to smell something odd (to me), but nothing was smoking, the gauges were all good, and it was still running. (Yes, I'm somewhat of a tractor newbie) Drove her back to her resting place, and noticed what I believe to be hydraulic fluid all over the right side of the engine and sprayed a little down toward the front right wheel. (I'll try to get a pic).
As I don't have a manual or any schematics, any thoughts? I'm guessing the PS shares the hydraulics and doesn't have it's own system. Would it be possible to put the PS on it's own to not overload the hydraulics? Does anyone have any drawings/schematics/manuals that I could use to try and work on this? I can find my way around things, but somewhat new to the hydraulics world.
Any information greatly appreciated.
CJ - Diesel newbie

 

[timwil]

Go over to johnstractor.com for a manual and more info

 

[Affordable]

Could be a hose leaking or possibly the pump,I think what you are smelling is the hydraulic fluid spraying on the engine.Take a good look at it,we have the hoses and pumps in stock if you need something

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

 

[RonMar]

Welcome. The answers you get might be a little more applicable if we knew a bit more about your equipment, like do you have a loader on it or any impliments? Also knowing about your environment such as what part of the country you are from would also be helpfull. Easiest way to do some of this is to fill in some info on your profile.

The demands of the steering are pretty small compared to the capabilities of the system. I would not change mine and I work the steering quite a bit on it. Mine has always been driveable with 1 finger against a steering wheel spoke. It sounds like you have a fluid leak. Check all the fittings for tighness then clean it off as best you can. Start it up and while watching(wear safety glasses) have someone else repeatedly cycle the steering or raise the 3 Point Hitch to load up the hydraulic system as you look for a leak. Sluggish steering could be caused by a few things, such as a low level in the reservoir, too thick a fluid or clogged suction strainer. Air leaking into the system along the suction line from reservoir to pump could cause erratic/sluggish operation of the steering, loader(if attached) or the 3PH lifting an impliment.

Do you know what fluid is in the system? If not already done, you should probably confirm that it has some actual hydraulic fluid in it instead of the chinese universal oil that filled all the resevoirs of my tractor when delivered(looked like straight 30WT oil, but smelled funny). Aw-32 is usually the reccomended fluid for the hydraulics unless you are somewhere extreme.

As suggested, quite a wealth of information(at least as much as the chinese manuals provide) over on Johns Jinma website under "Jinma Info" He has pretty much all the exploded views and parts lists available there, as well as some user submitted modification and maintenance information. johnstractor

Searching this chinese section will give you a wealth of info on flushing and filling reccomendations.

 

[cjax]

Thanks, and sorry about not giving many details. Had difficulty getting my accoutn activated, and when it finally was needed to post!

I have a JM254 with a Koyker Loader, and 6'finish mower.
I live in Central Indiana, but my property is very hilly. I mow about 9-11 acres (still debating 1 section), and use/will use the tractor for moving stones and dirt, and bush hogging/mowing. Dirt to fill in holes and troughs in the yard, the stones will be removed from the yard (over 45 found so far that I am not able to lift with leverage, so 200lb+) and used to line the parking pads and bound "decorative" areas in the yard.
Hope that helps.
The sluggish steering felt like it was bogging, which lead me to think the fluid level was low. I bought the 5gal bucket of AW32 last weekend, but I am not sure exactly how I will go about changing it out yet. Still working on that.
Thanks for the input!

 

[RonMar]

Search this forum for "flushing" and you will most likley come up with a few ideas on the subject. Some advocate flushing with kerosene before adding the new fluid, some do not. Kero is pretty tame and will not do any damage. It's different flow characteristics and solvent properties will help to clean out dirt and contaminants and get them back to the resovoir. At any rate, 2 fluid changes done correctly will get the majority of the original oil out of the system. I start by getting the tractor/fluid warmed up. I line up a open place to park where I can elevate the front end. A set of auto drive up ramps works good, but jacking the front end up and placing on jackstands so you can cycle the steering is better. I set up in an area that will allow the loader to go to full height. I park the tractor, front elevated then raise the loader to full height and 3PH to it's lowest, and shut down the tactor. I open up the drain, which on the 200 series is on the rear(lower left hand corner) of the hydraulic reservoir and dump the fluid. A large drip pan is best for this as the fluid runs down the rear structure, messy at best... The little bit of front elevation helps the fluid to drain out fully.

Once drained, I cycle the steering wheel full left to right till it stops working due to air in the system. the steering control valve connected to the wheel is also a vane type pump and will draw the fluid out of the pump and supply lines. Then I get off the tractor and try and turn the front wheels left to right to force as much fluid as I can from the steering cylinder. Once this is done, I use the loader control to first dump the bucket. Gravity should pull it down, but if not, have someone give it a tug while holding the lever to get it started. When the bucket is fully dumped, I then lower the loader. Since the reservoir is empty and the steering work should have drawn out most all of the fluid from the pump and main lines, mostly air will be drawn to the loader cylinders as gravity forces the loader down and the fluid in the cylinders back to the resovoir.. If done correctly, you should get the majority of the fluid out of the system, with only that left in the lines that had nothing left to push it back to the reservoir.

If flushing with Kero, replace the plug and fill the reservoir. Cycle the 3PH up and down to insure the pump is flowing fluid and clean out the rear valve. If the pump does not readilly prime, a little air pressure applied to the air vent pipe may help push fluid along to the pump. once the 3PH is operational, start cycling the steering back and forth. Top off the reservoir to make up for the fluid sent to the steering valve and cylinder, then start working the loader, and top off the reservoir as the loader cylinders and system are filled. Cycle all cylinders and valves repeatedly, then repeat the drain procedure and refill with hydraulic oil. The kerosene will eventually evaporate from the system, so monitor the fluid level frequently for a few months. Or a second oil change will get probably better than 98% of the kero out.

One additional step I did was, with the drain plug removed, remove the hydraulic strainer assembly from the front of the reservoir. Using a small windshield washer pump and a 1/4" curved aluminum pipe to reach down into the hole, I sprayed and flushed the reservoir bottom with kerosene. The bottom of the hydraulic reservoir is not flat/smooth. It is divided into several compartments by small casting stiffners/bulkheads. Mine was full of metal shavings so I flushed as much of this as possible out the drain plug.

 

[cjax]

RonMar,
Thanks for the write-up. I'll be doing all of this tomorrow. Hopefully tighterning things up and a new filling of good fluid will do the trick. The guy who had it before me wasn't the brightest bulb in the bunch, so he probably didn't do much of anything with it other than mow his lawn.

I'll let you know how it all turns out, and try to take pics along the way!

 

[cjax]

Ok, I did my Hydraulic flush and fill today. Wasn't too bad of a project really. Had it been one continuous project, it might have taken about 4 hours. Needless to say, were I do do it again, I could do it in less than 2, but I learned a lot about the system today!
Started off by trying to remove the knob on the front of the hydraulic reservoir, thinking that was the filling point. Little did I know it was for a single hydrr. set I don't even use (yet). Well, I broke the knob off in the process. No really big deal. Life goes on.
Got the tractor set up and on jack stands so I could operate the steering without problems. Raised the loader all the way up so I could dump those fluids also.
Then I went to draining the fluid. Man was it black and crappy! full of metal junk and just overall very nasty. Worked the power steering to empty its fluid, then dropped the bucket about half way, tipped the bucket all the way forward, then worked/lifted it back up to half way, and dropped the loader all the way down. That got quite a bit more fluid out of the reservoir. Then worked the 3ph to get what little was in there out. That wasn't much.
I then removed the hydraulic filter and cleaned it up, all nice and shiny like. (well, sort of)
I filled it up with Kerosene and closed her back up. Put her through her paces, stopping once to add a little more as the reservoir was emptied, and verified I had run all hydr equipment/controls possible. They all worked
I then drained the kero, and it was dirty. Very dirty. but I felt very happy with the results, as I knew it had removed a LOT of the crud in there. I used the drained kero sludge to clean some of the parts, like the filter, to a much nicer state. The inside of the reservoir was in tremendously better shape, as it was not longer black, but a bright orange when clean! Pretty cool to see.
Next I filled her back up with new AW32 from Napa, and started her back up to test he operations. Everything worked, except the 3ph.
WTH??
Well, we tried topping off fluids, that didn't work. Removed the filter area, and that didn't work. Noticed it was really heavily loading the engine when trying to raise the 3ph, so we figured there was a blockage. We removed 2 different bolts/assemblies from the 3ph pump area, to no avail. Disengaged the FEL and tried again, Still a no go. Then just on a shot in the dark, loosened up the from pump bolt (the one I had broken the knob off of earlier) and POW! It worked!. (Still not sure what we did there)
Anyway, I found if I leave that about 1/4 turn from tight, everything works fine, so, that is where she stays for now. Any thoughts on that?
Anyway, during all of this, I found one of my FEL couplings had some loose fittings. Tightened them up, and everything is now great. Runs great, no boggy power steering, and runs like a champ.
Also got out the grease gun and lubed EVERY zerk on this bad boy.
All in all, a very productive PM day, and I learned a lot I never knew about hydraulics today. Fun project for a first timer.
Thanks everyone for your assistance!

 

[bluechip]

The knob you broke is for restriction of flow out of the lift cylinder to slow the lowerin of the 3 point (or to lock it in the up position to keep an implement from accidently plowing up the road, etc. As you discovered, the 3 point does not work with this valve closed...

 

[RonMar]

The knob you broke is for restriction of flow out of the lift cylinder to slow the lowerin of the 3 point (or to lock it in the up position to keep an implement from accidently plowing up the road, etc. As you discovered, the 3 point does not work with this valve closed...

When closed fully, it also prevents fluid from entering the 3PH cylinder and forces fluid to the rear Quick Connection, the lower one pointing straight back in one of your pics. This I am assuming was for feeding a single acting cylinder in a dump bed trailer. You close that knob fully, connect the dump trailer hose and raise the 3PH lever and the bed will dump. You lower the 3PH control and the bed lowers by gravity and sends the fluid back to the tractor. I also see you have another QC back there pointing upward. Does that connect to the side of the reservoir? If so you also have a hydraulic return line so you could feed an open centered control device like a log splitter(slow one at 5GPM). Unfortunatly it cannot be used at the same time as the 3PH so it is not really suitable for a top and tilt setup. That sound you heard while trying to raise the 3PH with the valve closed was the hydraulic safety valve in the 3PH control valve relieving.

That speed regulating valve can be kind of tricky. Yours may have a floating valve point. I have heard some are solid. The valve is a little pointed cone that sets in a cone shaped seat. On the floating point type, the point is pinned to the shaft that you turn and can move up and down a little. That is so full flow can go to the 3PH when you raise an impliment. The flow in, from below, just pushes the point up out of the way. When you lower the impliment, the pointed tip drops down toward the valve seat and restricts the outflow so the impliment dosn't slam into the ground. Kind of like an adjustable check valve. The solid point valve would restrict fluid in both directions.

I usually set mine so the impliment goes up and down at the same speed. This is the tricky part though and requires small adjustments and tests for lowering speed. I usually turn it a single handle point at a time then check the lowering speed. With the floating point type, If you tighten it down too far, the impliment will go up, but won't come down. The hydraulic pressure on the valve from the impliment weight will also trap the valve so it won't turn. If this happens, you either have to try and turn it while sending pressure to the 3PH to raise it, or jack up the impliment to relieve the pressure and allow you to turn the valve.

You should probably take the valve all the way out to make sure the threads are clean and lubricated. They may be dry and rusty. You will also see what type you have, sliding point or solid point. There is a small standard head screw in the front of the block that the valve is screwed into. You need to remove this screw to unscrew the valve(prevents accidental removal and a hydraulic shower)

Glad everything worked out for you.