Help needed - leaking hydraulics issue

Hey all,
Have an odd problem here.

It appears that I am leaking hydraulic fluid from my Jinma 454LE. The funny thing is that I can't find the leak. I have topped off the hydraulic fluid twice over the last week or so - did again Saturday when I put a little over a gallon.

I went out and checked the engine and tranny/rear axle oil levels this morning. The engine level looks good. A little high, but, she's been sitting a while and at a slight incline. The level is at the high side of the high/low markings. I do not think that I am leaking into the engine.

The tranny level, on the other hand, is about to overflow when I removed the fill cap/dip stick. It appears to me, that the hydraulic fluid is leaking into the tranny. Is this possible? I don't see how looking at the parts diagram. The hydraulic reservoir and the tranny/rear axle areas are separated by a plate on the bottom of the hydraulic sump. Very odd though how when I checked the tranny fluid Saturday, it was not running out the top. I put in over a gallon of hydraulic fluid Saturday, it's now gone and the tranny is full. I do not see any puddles nor leaks.

Anyone have any thoughts? I am at a loss right now. Trying to avoid removing the hydraulic case.

Thanks,
Eddie

It has to be going some where, I would add another gallon to the tractor and let it sit for a day. Do not run it. then check your levels again. If it is leaking into the tranny it should be obvious. /forums/images/graemlins/confused.gif

Check your engine oil level. If you have a hydraulic pump seal leaking it will pump/leak the hydraulic oil into the engine crackcase. If this were the case eventually it will start coming out the crankcase breather or worse possibly hydrostatically lock the engine.
Harry

Dosn't that thing have 2 hydraulic pumps? One engine driven that feeds the power steering and the other driven off the PTO in the rear gearcase to power the 3PH, FEL, ECT(need to have PTO engaged to raise 3PH)? I thought the larger Jinmas used 2 pumps. If so, that main pump could be leaking into the gearcase, just as the single pump Jinma's sometimes leak into the engine. You could also have a bad casting on the plate that separates the hydraulic resovoir from the rear gearcase.

Hey guys - thanks for the info.

Ron,
It does have an engine driven pump, see attachment, with (2) sides / sets of impellers. One side (front/rt side in pic) that drives the power steering and the other side (back/left side) that powers the FEL. Not sure if there is a pump in the sump casing that drives the 3PH. I do know that the PTO does NOT have to be running to raise the 3 PH. At least, I do not do anything special such as engage the PTO to raise the 3 PH; typically leave the PTO disengaged. I just pull the lever. I will test when I top off the hydraulics – make sure the PTO is disengaged and raise the 3 PH.

From my research, it appears there is a large piston that provides the force the raise the 3PH. I have not found any mention of a traditional pump inside the sump. The parts diagram does not show a pump. I thought the piston was being supplied pressure from the engine pump – could have misunderstood.

I'm with you in that I believe its leaking into the gear case. The engine oil level looks good. As others have mentioned, I want to top off the hydraulics again and very closely monitor the levels. I need to drain off some of the tranny fluid though before I do anything – it’s about to overflow the fill cap - the reason I believe it’s leaking into the tranny.

Trying to avoid pulling the hydraulic case – looks like a pretty intense job. But, it’s looking more and more like I will have too.

Thanks again all. Will keep you posted.

Eddie

Eddie,
I have the 2005 454 model. I am sure it has only the double hydraulic pumps that run off the engine. No other hyd. pumps. Like you said, front one runs the power streering and the rear pump runs the 3pt lift and on mine the ZL-40 FEL. The rear hyd. in/out pipes run into the lift box. Must be leak between cases. Please let us know what you find.
camman

Hey guys,
Here's the latest:

Last night when I took the dip-stick cap off the tranny (below the seat), fluid came pouring out. I drained some out and am watching and measuring. Between last night and this morning appears to have risen a 1/4". Going to watch until it stabilizes then top off the hydraulics - see what happens.

Some more background:

I first noticed something weird with the hydraulics Saturday before last (2 weeks ago). I spent a couple of hours leveling a HUGE dirt pile on the property line between us and a neighbor. I then changed the front axle and tranny/rear-axle fluids. I then topped off the hydraulics - actually overflowed the reservoir. I did not drain any, just decided to let it run out over time. Got on the tractor, and took her about a mile down the road - on pavement - just to let the fluids settle for a re-check and top off when I get back. As I was going down the road I heard something lightly scraping behind me; just barely making intermittent noise. Turned around and looked and the box blade was just barely touching the pavement on one corner. Thought my leg must have hit the handle and lowered it down. When I reached for the handle, noticed it was pretty high. I pulled it up and the BB rose right up.

When I was going down the road, was in 3rd gear high - moving along pretty good. At one point I pulled to the side of the road to let a car go by and hit a real bumpy area. This was AFTER the BB was touching the road. Not sure if this (flying down the road) caused too much pressure in the 3PH hydraulics with the BB bouncing or what. I have done this before.

Now for the past several months, when I raise the BB too high, all the way to the end of the bracket, the engine will slightly drag, nothing major, just like it's under a little strain and I will push the handle forward some - everything is then alright. I have since put a bolt through the bracket so that I can't pull it all the way back.

Drove on down the road, turned around and came back. Kept an eye on the BB and it noticed it had lowered a couple of times. Would give the lift handle a nudge and it would pop back up. As I was pulling in the driveway, neighbor caught me and asked if I could spread out some dirt on his garden. Went over and was working on this. After about 15 minutes, the FEL and BB got REALLY jerky when I would try to move them. Was about done and headed home. Shut off the tractor, checked the axle & tranny fluids. When I got back on to move/park, the FEL nor BB would raise. Checked, could not find any leaks. Checked the reservoir and it was bone dry. Filled up with what I had left. Was able to raise the FEL and BB and park the tractor.

Past Saturday, topped off the hydraulics and was able to move. Everything was fine. When I checked Monday, the reservoir was bone dry again.

In doing research I read where the 3PH piston can extend past the cylinder. Was thinking this might be what was causing the engine to drag when I lifted the 3PH too high. I am to understand that repeated extension of the piston past the cylinder will trash the rubber piston O-ring; but the symptom is loss of lift for the 3 PH. Can't find any mention of where fluid will drain into the tranny. I have experienced loss of force on the 3 PH - the FEL is fine. Noticed last night there is a casting like cap where the top link joins the reservoir. The cap has a rubber seal on it and appears to be joined to both the reservoir and the back of the tranny/rear-axle. May have something leaking there down into the tranny??? May try to pull that off this evening to see what's in there.

Don't understand why the reservoir casing is upside down. Sure would have been nice to just remove the seat then take the top off the reservoir. Would like to see what is happening when it's filled with fluid.

Will try to get some pics once I tear into this.

Thanks all for the help - will keep posted.

Hmm.. the 3pt making the engine lug down with the 3pt at max travel makes me think some linkage is adjusted incorrectly, not shutting the lift cyl off at max travel.

Not that this adresses your hyd issue.. but in general when you are loading the engine down via the hyd pump, you need to look at everything involved.

Soundguy

I cannot say what the initial cause was but it sounds like the leak is in the TPH cylinder/piston. Leakage would end up in the tranny.

Hey Soundguy,
Agree with you looking at everything and the linkage traveling too far. I was just too lazy to do anything about it - guess I am paying for it now. Lesson learned not to let things linger around. I was totally unaware of how the piston worked. Assumed I was feeding too much fluid to hydro motor. Once I backed off, everything was good.

I know now!! /forums/images/graemlins/blush.gif /forums/images/graemlins/blush.gif

Plus, got it fixed. The link can no longer travel the max distance. Stops about an 1" short of what use to be the max travel.

Hi psj12,
That is what I am thinking. Does the 3PH piston have a drain, or open to the tranny? The casing I noticed last night, where the top link attaches, looks like it spans across both the reservoir and the tranny. Not sure what it looks like underneath, but, if there is an opening my bet is that's where it's going. Given that the FEL has always been fine, that's my guess as well - something in the 3PH piston. Hope to investigate tonight if I get home in time.

Thanks guys. Will let you know what's going on.