Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-22 162234
Was mowing my property yesterday with my tractor, Jinma series 200 (one of the smaller ones). All of a sudden my power steering went out, as well as my ability to lift my loader or the rear mower deck. Basically, no hydraulics working.
I took the seat off and took off the 3 bolts so I could pull out the screen and take a look at the hydraulic fluid. Everything looked good. Screen was a little dirty. CLeaned it up and put it back in.
THen I removed the pump and took it apart to look for problems. All gaskets OK, pump turned fine and looked clean. I put it back on, primed it by blowing compressed air in the reservoir, but left the outgoing connection off of the pump. Turned the tractor on briefly and fluid came pouring out. So I guess the pump is OK.
I put it back together and it is still not working! I am new at this. Is there a filter somewhere, or is that screen it. What else can I look for!? Lost?
Thanks,
Jim
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Hydraulic issues with my Jinma
Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada Pics |
2009-04-22 162235
Sounds like you may have a problem with the pressure relief valve.
If it goes bad, something as simple as a broken spring will do it, the fluid just gets dumped out of the pump straight back into the reservoir.
You need to put a gauge, one with a maximum of 3,000psi rating, on the system and see what if any pressure you're getting.
Best of luck. ....
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Hydraulic issues with my Jinma
greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky Pics |
2009-04-22 162236
For some reason, Jinma never saw fit to employ pressure relief in the 200 Series. In most cases, pressure relief consists of the gasket between the pump and the pump drive. Check your dipstick, see if your engine oil level is higher than it should be. If yes, the pump seal is gone.
The reason it "looks" like it's pumping, is that there's no load with the output hose disconnected. Hook that back up, and the hydraulic fluid will end up in your engine oil pan. Not a big job replacing the seal, just messy - and costs you an engine oil/filter change to boot.
//greg// ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-22 162240
OK, will give that a look. Thanks. ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-22 162241
Engine oil looks good and is at correct level.
The first thing that the pump goes to is a box underneath the steering wheel. Could there be something wrong there?
I am at a loss at this point.
Not sure what good troubleshooting things I can try. ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-22 162242
When I first looked at the reservoir, by the way, it looked a little low. Could some air have gotten in the system that I need to flush out somewhere? Just guessing. ....
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Hydraulic issues with my Jinma
greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky Pics |
2009-04-22 162249
Quote:
|
Yours is a vented system - which by design is self-priming. And if air got into the system, at a minimum you'd see bubbles when the tractor is running. Steering and lift would get jerky before it actually quit due to lack of fluid. A bad enough air leak can foam fluid right out the vent and down the back of the tractor. Low fluid will make for jerky lift operation and intermittent hard steering. But if you can still SEE it - you're not that low. My hydraulic dipsticks have only one line on them, I consider that the full mark. I never top up the hydraulic fluid until the dipstick comes out dry.
What you describe usually turns out to be either a plugged up (or collapsed) suction strainer - or a bad pump.
I don't recall you mentioning a loader. If so equipped, is that not working either?
//greg// ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-23 162251
I do have a loader, and it also was not working.
I have since bypassed it to get it out of the picture.
I took the pump apart. It seemed in good working order, and all gaskets and seals looked good also, although not sure what I would be looking for.
I cleaned the strainer, but it seemed OK.
The quick disconnects are the ball type. I can press in on the ball, which seems to be spring loaded. So I guess that is in working order to.
I will get at it again tomorrow. I probably need to figure out a better way to determine if the pump is working correctly under pressure. I don't have a pressure gauge.
Thanks to Greg and Murf for your help on this so far. ....
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Hydraulic issues with my Jinma
greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky Pics |
2009-04-23 162254
Taking the loader out of the equation was a good move. Unfortunately you can't do that with the steering or rear lift, because they're part of the same loop. The priority valve acts like a part-time Y-connector. When fluid is not needed for steering, the loop is strictly sump>pump>lift>sump. When it detects feedback from the steering controller, the priority valve permits the steering portion into the loop. At that point it's more like a figure 8; lift part of the loop still works, but the added steering part is priority valve>steering controller>steering cylinder>controller>priority valve. So you see that a plugged priority valve SHOULD leave you with either steering OR rear lift. But since it's relatively simple to remove-clean-replace, that's better that scratching our collective heads.
Besides, temporarily removing the P-valve will also permit you to confirm that fluid is in fact passing through the QD. But like I said, your symptoms really are more consistent with a plugged suction screen or a bad pump.
//greg// ....
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Hydraulic issues with my Jinma
auerbach
Join Date: Sep 2007 Posts: 2168 West of Toronto Pics |
2009-04-23 162257
Sounds like you got the answers you need, but if not, there's a site called Chinese Tractor Owners Association. ....
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Hydraulic issues with my Jinma
chipuren
Join Date: Jul 2003 Posts: 193 Arkansas |
2009-04-24 162295
The PR valve is in the lift box, so it does not affect the loader or steering. the priority valve is a pressure regulating valve as well. The loader is normally plumbed to be the first valve after the pump. The loader should work if the pump is developing pressure and the check valve in the quick connect is not closed. by bypassing the loader, you eliminated one check valve. When you took the loader out of the circuit, did you reconnect the two lines still attched to the tractor? Basically, the loader would lift (if plumbed as most are) regardless of steering priority valve or 3 point pressure relief valve malfunction as the loader valve would cause pressure to build ahead of those devices. ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-04-24 162297
Yes, that is a good point. The loader was the first thing off the pump before I removed it. Yes, I then hooked straight into the steering, which I assume is how the tractor is from factory without a loader.
The loader didn't work before I unhooked it, and the steering didn't work after, so this is looking more and more like the pump. Maybe it is time to invest in a pressure gauge and just be done with it.
Thanks,
Jim ....
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Hydraulic issues with my Jinma
kalpia
Join Date: Nov 2003 Posts: 77 Extreme Western on the beautiful St. Croix River, WI |
2009-06-02 163139
A little off topic but what's the recommended hydraulic fluid for these and the best way to clean the system? I'm doing much the same on my 2920 and might as well do it right as long as I'm fiddling with the front axle.
Thanks ....
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Hydraulic issues with my Jinma
bezanson
Join Date: Apr 2009 Posts: 8 Snohomish, WA |
2009-06-02 163140
So what I am going to do, and what has been recommended to me, is to fill the hydraulic system with Kerosene (some use Diesal, and pump that through the system for a bit and drain & clean the filter screen or replace.
The proper fluid would be the AWO32 (or is it AWE32? don't have the bucket in front of me).
Someone with more knowledge them me can confirm if this is the way to go.
On a side note, my drive coupling was shot because the pump was turning hard. so it stripped. Replacing both the pump and drive coupling. Parts are ordered and should get to work on it later this week. Meanwhile, I should be able to do the Kerosene flush without it. I can rig something onto a drill to get the pump to turn. ....
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Hydraulic issues with my Jinma
greg_g
Join Date: Jan 2004 Posts: 1816 Western Kentucky Pics |
2009-06-02 163142
Quote:
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Even though kero is more expensive than diesel, the difference in volatility and specific gravity mean less kero is left behind in the system after flushing. Drain old fluid and refill to normal level with kero. Start tractor and drive in figure 8s (to pump the kero through the steering circuit). Raise/lower the TPH several times, and the loader if so equipped. Drain kero through a screen or cloth to catch the big chunks. That way you can pour the once used stuff back in if you want a 2nd flush. When no more chunks get caught in the screen, replace the drain plug and refill the system with fresh hydraulic fluid. Do the figure 8 thing again and exercise the lift/loader. Then let it set overnight. What little kero is left should settle to the bottom of the sump. Carefully remove the drain plug to let it out. Top up again with hydraulic fluid as required.
//greg// ....
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Hydraulic issues with my Jinma
kalpia
Join Date: Nov 2003 Posts: 77 Extreme Western on the beautiful St. Croix River, WI |
2009-06-03 163152
Thanks, I'm starting a simple list of items & fluids that can be used and purchased locally (when possible). I don't know if anyone has such a list but when it's more complete I'll make it available to all. I might not be relevent for all but it sounds like much of these things are common for many of the CUTs out there. ....
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