Jinma Hydraulic Pump - Failures

   / Jinma Hydraulic Pump - Failures #31  
Circle D - I think you are on the right track. I did not have the extra direct relief valve installed when I put the 20ml/r pump on. Thinking about it, I am sure that the original system would be marginal at best, but with higher engine RPM, failure would most likely occur quickly. That is what happened in my case I am sure.
I should mention that when the QD are removed from the pump outlet (pressure side), you will see the hose to the FEL valve block has a smaller internal dia - maybe 5/16" dia at most. The short pump discharge hose has a bigger ID of around 1/2" The relief vales in the valve blocks may not be too efficitient IMO.

I have since added a 10gpm external relief valve in hyd.pump discharge line and set it to open at 1800psi (18 bar). For what I need the 1800 psi pressure is adequate. I have the hose from the relief valve returning to the hydraulic tank. Set up seems to work well so far. Will try to attach a couple of foto's (taken just a day or two ago) to show what I have done - very similar to what other owners have done also.

Without the extra relief valve it will become expensive - the external relief valve is essential IMO.

Cheers

Jim

I think you have a small typo...in bar, you are running ~ 125 bar. Just clearing up the typo, the work looks great, and I'm jealous my tractor doesn't have an external relief like yours.
 
   / Jinma Hydraulic Pump - Failures #32  
1,800 psig = 124.1056 bar or 122.4827 atmospheres.
 
   / Jinma Hydraulic Pump - Failures #33  
Trying to figure out how the hoses on a Jinma 454 is supposed to run. Installed new pump and need to know if anyone would have a picture to show how to route the lines. Thanks
 
   / Jinma Hydraulic Pump - Failures #34  
Sounds like several of my problems and questions have been addressed here. I will get a new filter to start, get rid of my quick connects in favor of direct threaded connections, and check for leaks on the intake side that be taking in air. I don't have any leaks coming out that are that noticeable, but may be taking in air and causing some squishness and slow responses to my hydro requests.
To be sure, I think I only have one location that holds fluid, you fill and check right next to the gear shift lever on top of the transmission. I do not see any other place that may hold fluid. If there is, I sure haven't changed it! Jinma 345 diesel. I think there is a breather at the back behind the seat, but no way to put fluid in there. I will add a pressure gauge to the FEL controls to see what that is reading.
One quick question, I have a hydro fitting at the back of the tractor near the 3 point. There is only one, what the heck is that for? I would think you need 2 to do anything, one power and one return. What good is one connection? Is there a return somewhere I can not find?
 
   / Jinma Hydraulic Pump - Failures #35  
One quick question, I have a hydro fitting at the back of the tractor near the 3 point. There is only one, what the heck is that for? I would think you need 2 to do anything, one power and one return. What good is one connection? Is there a return somewhere I can not find?

My 304 has a quick connect for a dump trailer on the left. I have a similar looking pipe on the right, but that's to drain the fluid. It could be made into a return easily.
 
   / Jinma Hydraulic Pump - Failures #36  
No - that fitting on the transmission is for gear oil, not hydraulic fluid. The hydraulic fluid goes in the lift box, where that breather is. Unscrew it and there's a dipstick. Do NOT put hydraulic fluid in your gear case!

The single remote is for a dump trailer, power up, gravity down.
 
   / Jinma Hydraulic Pump - Failures #37  
I spent $2500 last year having the case split to repair busted off shift forks, and the shop put hydraulic in the gear box. They said it ran the whole tractor.
I might have to go look all this up and do some draining/filling if that is the case.
 
   / Jinma Hydraulic Pump - Failures #38  
I spent $2500 last year having the case split to repair busted off shift forks, and the shop put hydraulic in the gear box. They said it ran the whole tractor.
I might have to go look all this up and do some draining/filling if that is the case.

The shop has no idea what they were doing. There is a separate hydro reservoir behind the seat.

Chris
 
   / Jinma Hydraulic Pump - Failures #39  
One quick question, I have a hydro fitting at the back of the tractor near the 3 point. There is only one, what the heck is that for? I would think you need 2 to do anything, one power and one return. What good is one connection? Is there a return somewhere I can not find?

Yep, that single fitting is most likley for a dump trailer. You close the 3PH speed regulating valve, connect the dump trailer hose to that fitting and use the 3PH control lever to raise/dump the trailer with fluid flowing out the fitting to the trailer. When you lower the 3PH control lever, the weight of the trailer forces the fluid back thru the fitting and into the tractor. This is the same as you do to raise and lower the 3PH which is also a single acting cylinder.
 
   / Jinma Hydraulic Pump - Failures #40  
Drained and filled the hydro with fresh fluid and everything works great again. Was not much to drain! Drained the gear case and filled that with all gear oil. It looks like a mix of gear oil and hydro. I should have known something was wrong with that idea, I have a barrel of each sitting in the garage from when I first bought the tractor 5 years ago and did all the changes from the factory gunk. She is running fine and sounds great now. I also had the cooling system apart to replace the lower rad hose and install a hot water heater. A flush and all new fluid with conditioner, and she is staying nice and cool now! I ran it over an hour sitting at a high idle and the needle stayed between 40 and 60 the whole time. My lil Virjinia is happy again.
 
 
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