Go Bottom

Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-21          173346


I have no experience with Hydraulic steering problems, so I'm looking for some advice to find the culprit.

Symptoms:
1) Standing still: turning the steering wheel produces no movement of the front wheels.
2) Moving: I get very "mushy" steering.
3) Front wheels off the ground: steering is fine.

From that, it seems like there is not enough force being exerted by the slave cylinder...? First I checked fluid level - OK. Then noted that the lift, loader frame, and bucket seem to operate with normal force and speed.

That would seem to exonerate the Hydraulic pump. Yes???

Am I right that this only leaves the slave cylinder and the steering wheel control valves? If so, how can I determine which is at fault [replacing a good part is way too expensive for an old coot living on Social (In)Security!!!]

I did a close visual of each part and the connecting lines and found no fluid leaks or obvious damage. Since the slave cylinder is located low up front where all the rocks are, I am most suspicious of it. But, no leaks and no dents....??? Hmmmm. With only 122 hours on the machine, I would not expect failure, except for external damage...??

Can a cylinder go bad without obvious signs of damage?
Is there a cheap test method to find out?

If anyone have "Been there; Done that", I would appreciate a sharing of their wisdom.......

cheers,
johnd




Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-21          173353


Your steering cylinder is bypassing, a commonly reported problem with the 200 Series Jinma of any age. One thing that can cause it is forcing the steering wheel to turn when the engine isn't running. But since it's a common problem, most Jinma dealers carry cylinder repair kits.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-22          173355


>Your steering cylinder is bypassing, a commonly reported
> problem with the 200 Series Jinma of any age.
Oh rats!, I was hoping that I wouldn't have to do
a tear down. No such luck.......

>One thing that can cause it is forcing the steering
>wheel to turn when the engine isn't running.
Never done that; no purpose to it.

>But since it's a common problem, most Jinma dealers
>carry cylinder repair kits.
Guess that it's just part of Chinese Quality. [The
starter motor went out at about 5->6 hours. But no
problems since. Oh well......]

I thank you exceedingly much! Now that I know the forum
is here, I think I'll hang around and learn a thing or
two. Gotta feeling I may need that in the future (grin).

cheers,
johnd ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-22          173357


The two biggest problems with the 200 Series starter motor are (a) dirt, and (b) insufficient voltage to the solenoid. Those who are not mechanically/electrically inclined will take the starter and solenoid to an auto electric shop for a good cleaning. That solves (a). Problem (b) can be remedied with the addition of an inexpensive Ford-type starter relay and some 10AWG primary wire.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-22          173361


>The two biggest problems with the 200 Series starter motor
> are (a) dirt, and (b) insufficient voltage to the
> solenoid.
I sorta think that it was neither in this case. The first
5 hours were mostly futzing around, checking it out with
no "Down n Dirty" operation. The replacement starter has
performed flawlessly, despite the Texas Hill Country Dirt.

As far as the electrical system goes, being a retired EE,
I looked at it with a critical eye. Don't like some of
what I saw but IR losses on the Battery and Starter cables
don't appear to be a problem in my case.....not yet anyhoo.


>Those who are not mechanically/electrically inclined
>will take the starter and solenoid to an auto electric
> shop for a good cleaning. That solves (a). Problem
>(b) can be remedied with the addition of an inexpensive
> Ford-type starter relay and some 10AWG primary wire.
Amen to the low resistance cables!! Double Amen. We got a
'48 plymouth with a 6v system. Anybody for ought gauge
cables!!!! Turning 3 diesel cylinders with 12v is hard,
but turning 6 gas cylinders with (maybe)6v is d@mn hard.

Any particular Ford series relays? [Got a old '79 ford
150 laying around awaiting it's turn on the scrap heap.
Maybe I could strip out the relay for possible future
problems.....which I hope never occur.....fingers crossed.]

At any rate, I really think that I had a bum starter.
And - perhaps - steering controller. That said, I still
love my little jinma and would buy it again.......
It's a little rough around the edges, but still a
sweet machine.

cheers,
johnd ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-22          173362


Could have been a bum starter. But years of working these Chinese tractor forums makes that the exception rather than the rule. Disregard if your tractor has one of the newer reduction gear starters. But if it doesn't, disassemble one - say a QD100C3 - on a brand new Jinma. Odds are it will be filthy inside. A compound of grease, metal shavings, dirt, salt, and moisture presents a physical resistance to pinion travel.

Then there's the wiring. Small gauge, sloppy crimps, cheap connectors all combine to result in a voltage drop at the starter solenoid. Solenoids like this need at least 10v to engage properly. 8v-9v and they'll chatter, but the pinion won't get thrown far enough to engage the ring gear. 7V and below, they just click.

It doesn't matter if you've got good voltage at the starter, I'm talking about voltage on the little wire that comes down from the starter switch to the solenoid that sits on top of the starter. When you find low voltage here, bypass all the losses with a relay like I mentioned above. When installed properly, it delivers full battery voltage directly to the solenoid - and gives the pinion the kick it needs to positively engage the ring gear.

//greg// ....

Picture Link


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-23          173376


>Could have been a bum starter. But years of working
>these Chinese tractor forums makes that the exception
> rather than the rule. Disregard if your tractor has
>one of the newer reduction gear starters. But if it
>doesn't, disassemble one - say a QD100C3 - on a brand new
> Jinma. Odds are it will be filthy inside. A compound of
>grease, metal shavings, dirt, salt, and moisture presents
>a physical resistance to pinion travel.
Aha, I see what you mean!

Lack of cleanliness in a shipped (new)part is just another
way of saying a bum starter, I think. I did not suspect
that particular lack of quality control, but it does make
sense that such a starter would experience infant mortality.

>Then there's the wiring. Small gauge, sloppy crimps,
>cheap connectors all combine to result in a voltage
>drop at the starter solenoid.
Exactly.
And my little jinny surely isn't wired the way I
would desire.....

>Solenoids like this need at least 10v to engage
>properly. 8v-9v and they'll chatter, but the pinion
>won't get thrown far enough to engage the ring gear.
>7V and below, they just click.
Right.
But when my starter failed, it was (apparently)
a winding burned open. I.E. the solenoid did not chatter.
I could hear it click once and the starter made no attempt
to turn. Ammeter did _not_ show the sudden drain that
you would expect if the starter stalled and was drawing
max current with no back EMF to limit it. also didn't
show the pulsing current from a solenoid kicking in
and out, applying and removing voltage to the
starter.....??......


Returning to my original question, may I ask for a bit
of clarification - my fuzziness, not yours! When you say
the cylinder is bypassing, I assume that you mean the
piston seals are "leaking" fluid from one side to the
other, without "pushing" the piston properly. Is that
correct? If that is true, how would applying steering
input with engine shut down, cause failure? Is there
still too much hydraulic pressure left over when
the engine(pump) is shut down?

Sorry to be thick. Electrical circuits are usually easy
for me, but Hydraulic Circuits...well, sometimes, I don't
have a hint of a suspicion of a clue.............

thanks again,
johnd ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-23          173382


Quote:
Originally Posted by dnaraG_1M | view 173376
I assume that you mean the piston seals are "leaking" fluid from one side to the other, without "pushing" the piston properly. Is that correct? If that is true, how would applying steering input with engine shut down, cause failure? Is there still too much hydraulic pressure left over when the engine(pump) is shut down?
Your assumption is correct John, one or more of the seals has failed. A cylinder repair kit will stop that.

Now, the steering wheel thing. Once the tractor is shut down, the pump no longer exerts pressure on the steering fluid. But consider that there's no air in the system (or shouldn't be). That thing at the bottom of the steering column is the hydraulic controller. you turn the steering wheel one way, fluid travels direction A. Turn it the other way, fluid travels in direction B. The physical act of turning the steering wheel CREATES pressure through the controller. You turn the wheel, the controller tries to push fluid one way or the other. But since the pump isn't running, there's nothing to return the fluid. But given enough pressure on the steering wheel, the pressure has to go somewhere. In extreme cases, it ruptures a cylinder seal in it's attempt to return.

When the pump's turning, there's a relief valve to prevent this. But when the pump's not running - it's just the steering wheel, the controller, and the cylinder.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-23          173383


>Your assumption is correct John, one or more of the seals
>has failed. A cylinder repair kit will stop that.
Got one on order (and a spare boot, just in case I
have fumble fingers!) from affordable tractors. They're
are almost neighbors - texas style, anyhow.

>way, fluid travels in direction B. The physical act of
>turning the steering wheel CREATES pressure through the
>controller. You turn the wheel, the controller tries
>to push
So there's where my misunderstanding was, Greg!
I *assumed* that the controller was just a set of valves
to DIRECT the pressure, not CREATE it.
Like I said "clueless".

In electrical terms, not a switch but a battery. D'oh!


Sooner or later, I learn a bit about the Hydraulics. Can't
see inside the "boxes", but have traced all the pipes and hoses. Mostly - along with your info - it seems to make
sense now. The only one that I haven't figured out yet
is the pipe from the "priority controller" to the female
Quick Connect next to the top link - no return pipe/hose!
I'm reading lots of old postings here so I suspect
I'll learn what I need to know before long.

The wealth of info is somewhat overwhelming, but thank
god it's here..!..

cheers,
johnd
....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-23          173389


The priority valve (some call it a diverter valve) is sort of a feedback device. And understand that what I'm about to describe only happens when the engine is running and the pump is pumping.

Absent input from the steering wheel, the primary hydraulic circuit is simply pump>sump>pump. It's primary purpose is to work the rear lift. In the Jinma 200 Series, steering is a secondary or slave circuit.

As I stated before, the steering wheel provides directional input to the steering controller. Physically turning the wheel activates the steering controller, which in turn tells the PV that it requires fluid from the primary circuit. The PV opens, permitting fluid to enter the secondary circuit. The PV then routes this fluid to the controller which passes it on to the steering cylinder (and ultimately back into the primary circuit). Remove steering wheel input, there's no steering controller intervention, the PV closes.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
dnaraG_1M
Join Date: Aug 2010
Posts: 17 central texas
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-08-23          173392


>As I stated before, the steering wheel provides directional
> input to the steering controller. Physically turning the
>wheel activates the steering controller, which in turn
>tells the PV that it requires fluid from the primary
>circuit. The PV opens, permitting fluid to enter the
>secondary circuit. The PV then routes this fluid to the
>controller which passes it on to the steering cylinder
>(and ultimately back into the primary circuit). Remove
>steering wheel input, there's no steering controller
>intervention, the PV closes.
Yes, that's what I had understood from my previous reading
of your, and other's, postings. Putting it in my own
words, I understand that to say that "if the pump is
running, the steering controller directs the pump's
pressure to the slave cylinder - but does not generate
it's own pressure to the cylinder".

I hope that's right.

But in your previous reply, you addressed what happens
when the pump is NOT RUNNING. In that case, you were
very clear that the steering controller CREATES it's
own pressure from steering wheel motion. From
combining these two concepts, I conclude that the
steering controller operates in two different
ways, depending on pump working/not working.

IE
1) Pump running -> the steering controller DIRECTS
the pressure from the pump to the cylinder.
2) Pump not running -> the steering controller CREATES
pressure on the cylinder. Pressure which can/does
damage the seals in the cylinder.

Boy, that sure was non-obvious to me at first. But then,
I really have no idea of the internal implementation of
the steering controller and, being a simplistic guy, was
assuming a simplistic valve setup. Those mechanical
engineers are just way too sneaky for me....(grin)..

cheers,
johnd ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-08-23          173395


Almost.
Pump running: primary circuit active, secondary circuit awaiting input
Pump not running: primary circuit inactive, including PV.

Forcing the steering wheel with the pump not running is simply forcing fluid to flow in the secondary circuit. But even though it's a secondary circuit, it's still a loop. Forcing the steering wheel causes the steering controller to "push" fluid toward the cylinder. But lacking a proper return, that fluid has to go somewhere. In some cases, it can damage a cylinder seal trying to get there.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
shishe
Join Date: Oct 2010
Posts: 7 Loma Linda CA
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-10-19          174640


Hi every one, I just bought a 2003 Jinma 284 and it comes with hydraulic problems reason for been reading all the good advices here. Thank for explaining so good about the starter I need to fix mine, at first I could not understand what greg was saying about turning the steering wheel while the engine is off and braking the steering cylinder, now is getting to me, correct me if I am wrong. The piston head surface area where the hydraulic fluid applies pressure is smaller on the shaft side than on the other side, let’s say the piston is 2 inches in diameter, in one side oil will apply pressure in the full 3.1416 square inches but in the other side it will be 2 inches minus the diameter of the shaft, if the shaft is one inch then the oil will have only half of the surface to work on, now if I apply let’s say 1000psi on the 2 inches side and I don’t let the oil drain on the other side of the piston then the pressure there will be 2000psi and this gradient may break the seal.

Now see if someone can give me an advice about my problem, I have no hydraulics at all, front loader steering or3ph, prior owner replace the pump (gave me the old one) same problem, I pulled the pump out and checked the gear, key and shaft, everything is OK there, then I disconnect the front loader, same problem.

Questions:
Assuming that the pump is OK and my problem is with the divert valve or the steering controller shouldn’t the front loader works as it is connected between the pump and the diverter valve?

Can I disconnect the 3ph at the diverter valve and plug the outlet to isolate the problem?

Can I disconnect the steering controller and plug the outlet for troubleshooting purpose

How can I check the pressure at the pump?

What else can it be?
....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-10-19          174643


1. yes
2. you can disconnect it anywhere, as long as doing so does not obstruct flow to the remaining circuit(s)
3. same answer
4. buy a pressure gauge
5. The one thing I didn't see in your troubleshooting, is whether or not you determined that fluid is actually getting TO the pump. Being a 2003 model, your tractor is unlikely to have external hydraulic filtration (unless it was added by a previous owner). These earlier models have a suction filter/screen inside the sump. Assuming minimal maintenance over the last 7 years, I bet the suction screen's collapsed. If in fact you DO have external filtration, suspect either an aftermarket installation issue - or the filter cartridge itself.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
shishe
Join Date: Oct 2010
Posts: 7 Loma Linda CA
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-10-19          174668


Thanks greg for your help.
The sump was so filled up with oil that as soon as the front wheels went on the trailer oil begun to leak from the sump vent pipe plug.

After removing the hydraulic pump a good amount of oil was coming through the pipe from the sump just by gravity.

The filter inside the sump was clean but it had pieces of the screen missing.

I remove the rear cover to look inside the sump and I found pieces of rubber O rings and pieces of white plastic rings, I will have to take a look at the 3ph piston as well.

At this time I cannot assume to have a good pump and I need to check the first thing first. The pump. I bought a 4000psi gauge at Harbor Freight Tools but I don’t know where to put it yet.

I am planning to add an external filter.

1. Where is the best place to put it? On the metal pipe just before the pump next to the starter?

2. Do we have to bleed the air out of the system or there is no need for.
....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
greg_g
Join Date: Jan 2004
Posts: 1816 Western Kentucky
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster  View my Photos  Pics

2010-10-19          174670


I don't recall the exact plumbing between the sump and the pump, but hopefully there's someplace you can open the line on the suction side. Rig it so the suction line will draw fluid from a bucket. If it does, you're gonna be filling that sump up again with the return. So open the first quick disconnect after the pump output, and let the fluid go into a 2nd bucket.

If you want a full time hydraulic pressure gauge, you should probably have a shop install for you. If you just want to have one in the tool box for testing, consider buying another quick disconnect fitting. Put the male half on one side of the gauge, the female on the other. Then open that same first quick disconnect and plug in the gauge.

You can put a filter on the suction side, but that risks potentially starving the pump. Or you could put it just before where the return line goes back into the sump. Some folks put them on the pressure line, but that probably should be done by a professional. Be careful when selecting spin-on filters. The difference in pressures among suction and supply and return lines require different filters (fine/coarse)

It's an open system, which means it's supposed to be self-priming/self-bleeding. But that assumes the vent/fill cap is working. I rinse mine out with diesel once a year, then blow the vent holes out with compressed air.

//greg// ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
shishe
Join Date: Oct 2010
Posts: 7 Loma Linda CA
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-11-05          174948


Finally I got it working, I have no doubt that this tractor had been abused and never taken care off but the engine is newly rebuild and transmission is in good shape so the rest is fixable, the 3PH was broken (blown seals) and the diverter valve was the main problem.
Question: What is the proper way to check the hydraulic fluid level? Screwing the filler plug all the way in or just letting it seat on top of the hole, that will make like an inch of difference
....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo



Hydraulic steering problem Jinma 284

View my Photos
richwaugh
Join Date: Mar 2010
Posts: 96
TractorPoint Premium Member -- 5 Tractors = Very Frequent Poster

2010-11-05          174953


On Chinese tractors you generally just set it on the edge but don't screw it in. For dipsticks that just pull out, you push those back in to read. ....


Reply to | Quote Post Reply to PostQuote Reply | Add PhotoAdd Photo


   Go Top


Share This







Member Login