HELP - replacing hydraulic pump of Jinma 454LE

[ejtaylor822]

NEWBIE QUESTION / FIRST POST...

(posted this in the general maintenance forum but was told might be better here in the Chinese Tractors forum)

New to the tractor world here. Have been addicted to this web site for about 6 months. Have learned so much from this site! After researching for months and using information from this site bought a Jinma 454 LE back in May. I was hoping to make my first post on a project I am doing and not a problem!

I was out clearing in our woods this weekend. I was turning around when this metallic like clank/whizzing sound started and quit before I could turn off the engine. I drove on but as I was lowering the bucket it would not move and there was hydraulic fluid spurting out from around the knob under the joystick and the cover on the joystick (Koyker 195). I shut off the engine and started looking around. There was hydraulic fluid all over the engine around the pump but the hoses looked fine. With the engine off, I put the joystick in "float" but the bucket would not lower. I tried to push down on the bucket but it would not move.

I went ahead and started her back up and put her back in the usual parking space. The power steering is fine but I still could not get the bucket to move. I turned the motor off and looked around again. Noticed hydraulic fluid all over the ground; left a good trail of it. That's when I noticed the hose coupling that runs under the brake side of the floorboard had come undone. I remember a sapling popping up under the floorboard and evidently it knocked the coupling loose. I tried to get the coupling back together but did not have much luck. Would move the collar back, insert the male end, but, just seems like I cannot get the male coupling inserted far enough. There is no obstructions and looks like it should just pop right in but I just can’t get enough pressure to get it fully inserted.

I know the hydraulic fluid is gone. I left a nice trail of it through the woods. I have been exchanging email with the dealer (Circle G Tractors – wonderful dealer and highly recommend) and he said the pump is probably blown. Going to call him tomorrow to discuss. He’s got one in stock and I feel alright with swapping the existing one out but have never worked with hydraulics – studied in college years ago – but no hands on experience. I have attached a picture of the pump. It looks like there are two “sides”, the PTO/Power side and the power steering(??). Once again, the power steering is fine – seems odd or is this normal?

I have searched through past threads and I am posting this to get any advice, knowledge, “beware of…”, etc. as I get ready to swap out this pump. Like I said I am a total newbie, have some mechanical experience and aptitude, but when it comes to hydraulics I am totally green. Is there a certain way/order to unhook the lines? Should the FEL be in float prior to unhooking the pump? Once the pump is swapped, do not think need I need to bleed the lines, but do I need too, and, is there an order I should reattach?

Once again totally green. Any and all help, advice, safety, pitfalls to avoid, encouragement, sympathy (makes me sick and have been “in the dumps” since my tractor is busted) is greatly appreciated.

Thanks,
Eddie

 

[Soundguy]

Can't comment on your specific problem.. but if your setup is one where there is a quick coupler in line with the pump, before any type of relief valve, and that couple pops off.. that WILL deadhead the pump. While window shopping jinma tractors I am always fascinated to see this plumbing technique on the tractors with the loaders.

Odd that you still have power steering, and the loader is up. Sounds like the pump is still generating pressure.. Have you tried relieving the pressure on the system by supporting the loader bucket and trying to re-attach that coupling.

Try to tracte down what line controlls the exhaust from the spool set.

Good luck with your repair.

soundguy

 

[JohnS]

Eddie,

I am not familiar with the 454 hydraulics, but assume you have a dual pump system. One, as you say for power steering, and other for 3pt lift, fel, and other hydraulics. There are different ways to install the hydraulics for the FEL, and your dealer is the expert on it. Unless you provided a hyd schematic, everyone here would have to guess. The pump sounds like a secondary failure, possibly caused by the coupling. Did they send new couplings/hoses?

Not sure why you can't lower the FEL, maybe it is the returnline coupling?, but you would want to get it lowered and take any pressure off it. Same for 3pt or any other hydraulics running off this pump. It should be a self priming pump, but it can't hurt to put some hyd oil in it, for the initial start-up. When you start it up for the first time, watch the hyd resevoir for fluid movement, and if the pump seems to get very hot , very quickly, shut it off, you still have a block or major restriction.

 

[RonMar]

That is unfortunate.

If I recall my studying correctly, the larger Jinma's use dual pumps, one for steering and another for utilities/lift.

Loosing a main coupling on the pump outlet most likley blew the pump seals(oil all over the engine) or damaged the pump shaft/drive gear(possible noises you heard or could have been oil escaping at high pressure as the seal let go).

From your description(loader froze in the air, fluid at control valve), it sounds like you lost the hose connection comming OUT of the loader control valve. Your description of fluid comming out around the joystick leads me to believe that it also was exposed to the deadhead pressure and may have damaged some seals in the valve.

The quick connections have check balls in them that the opposite connector opens when seated. These can only be made up when there is NO system pressure. The weight of the suspended loader may be putting pressure on the system preventing you from re-seating the quick connection. Block and jack-up the loader bucket to get ALL the pressure off the system then try re-seating the quick connection. Once that is done, you should be able to lower the FEL. I know you were trying to use the float to lower the loader but I think that the load check valves in the control valve still need system pressure to overcome the weight of the loader. Without knowing exactly how your loader valve is configured, it is hard to say how it is designed to operate.

<font color="red"> </font> Please be carefull and dont at any time place yourself in a position where the sudden drop of the bucket would injur you or anyone else. Since you got fluid to come out of that valve, it's functionality is now suspect. Once you re-connect that return line and give the trapped fluid a place to go, the loader may come down on its own once you remove the blocks. These machines can kill and gravity is a real *&^%$, don't turn your back on her for a second. And of course when working with any potential sprayed/splashed fluid wear saftey glasses.

<font color="black"> </font>
Once the loader is down and ALL pressure is off the system, replacing the pump should be a pretty straightforward affair. Two pipe fittings and a few mounting bolts. With a little luck it only blew seals and didn't damage the drive but of course you are going to inspect that carefully Once you re-assemble the system and re-fill the hydraulic resovoir, start the engine and the pump should self prime(here is where you should really wear saftey glasses). You will need to cycle all the controls to purge all the air. I would not be suprised if the loader valve leaks or even sprays fluid. Hydraulic leaks don't get better, they just get worse. Since you were able to get fluid out past the spool "O" rings once, it will probably be a regular thing now.

The following links to John's Jinma site may be usefull. I believe they are for smaller jinma's but the basic info is sound. Both of these links describe a failure similar to yours with differing results. Please take note of the use of tie-wraps on the quick connect couplings in the second link to lock them in the coupled position. As the title on that page states, it is cheap insurance.

http://johnstractor.homestead.com/HydPumpDisassembled.html

http://johnstractor.homestead.com/25Insurance.html

Good Luck

 

[ejtaylor822]

Soundguy, John and Ron,
Thanks for the information and knowledge sharing. From the feedback I have gotten from this site and talking with the dealer it definitely looks like the pump is shot. The dealer, Circle G Tractors, shipped me a new pump yesterday and I should have it by the weekend.

Soundguy and John,
It's a dual pump system and you are right - that's why I still have power steering. The dealer told me, and it sounds like you have seen it as well, that when those hoses come uncoupled, the pump goes. Couldn't understand at first, but, it now makes sense with the back pressure coming through the send lines and crashing the impellers. I have my FEL supports in place. Once the new pump is in, going to move and get the pressure off of the FEL and 3PH.

Ron,
Thanks for the detailed information - that's a big help. Appreciate the emphasis on safety. I could see where a little carelessness and inattention could really mess up your day; especially with all the pressure there seems to be in that system right now. I will take a good look at the drive and make sure that's alright - thanks. The pump is self priming but I am still going to add a little in the chambers as I install. Here's the kicker!!!!!!!!!!!!!! I saw that post on John's website about the wire ties on the couplings. Even bought some special black ones and guess what, they're still in my tool chest, waiting for when I have time to install them!!!!! Guess I'll make a little time when I swap the pump! /forums/images/graemlins/wink.gif

I am going to document/photograph removing the pump once I swap it out. Would appreciate any feedback once it is up. Could not find a lot of information on this process, mainly with hydraulics systems, and maybe this will help the next newbie.

Thanks again all!

 

[ejtaylor822]

Well, got the pump swapped out tonight. Everything is running great once again. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

I am still going to document swapping out the pump for the Jinma 454, but, wanted to post this picture of the old pump. I did not expect THIS kind of failure?!?!?!?!

Is the split housing normal when a pump goes? I was expecting to see a blown gasket, or the impellers crashed, but not a cracked housing.

Anyway, it was a hot and interesting evening.

 

[ejtaylor822]

Here's another of the housing from inside of the cavity.

 

[RonMar]

Cool!
But not especially surprising. You slam the door on a high energy hydraulic flow and that energy has to go somewhere. If it didn't go out through that crack, it would have gone somewhere else or damaged the drive. How is the loader valve?

Ron

 

[ejtaylor822]

Hey Ron!

I am happy to say the loader valve, so far, is fine. However, I have not put it under any load yet; outside of just excercising the system. I am moving a large mulch pile for a neighbor this morning though, so should know more then. But right now I see no fluid at all.

That certainly is a lot of energy. I just didn't expect the housing to crack. I expected gaskets or something else. I'm definitely with you though, rather see the housing than the shaft or other engine parts give way /forums/images/graemlins/laugh.gif. So the housing crack is pretty common?

Thanks again for the help and advice.

 

[Harrygoodwrench]

</font><font color="blueclass=small">( quote)

That certainly is a lot of energy. I just didn't expect the housing to crack. I expected gaskets or something else. I'm definitely with you though, rather see the housing than the shaft or other engine parts give way /forums/images/graemlins/laugh.gif. So the housing crack is pretty common?

When the quick disconnects come apart with the engine running most often its the pump front seal that blows and fills the crankcase with hydraulic oil, however I have seen I believe 2 pics other than yours of a cracked pump housing. So it is a definite possibility but I wouldn't say common. Either way its a component failure, one being a more expensive failure.
Thanks for sharing.