Total hydraulic Loss

[Rich Waugh]

When you put the output line from the hydraulic pump into the bucket, be sure to remove the quick connect from the end of it. If you run the pump with the quick connect uncoupled but still on the hose end, you'll be deadheading the pump and can surely blow either the seals or the pump casing.

It is fairly normal for these tractors to lose a bit hydraulic fluid from the breather vent on the lift box when going up hills. They just didn't leave enough clearance for the fluid to slop around in the lift box and so it get out the vent sometimes. One cure for this is to replace the breather vent "mushroom" with a hose nipple and run a piece of flexible tubing up to one of the ROPS arms and install the mushroom there. You'd have to turn the tractor over to get it to slop out after doing that. :laughing:

Yes, my dipstick plug screws in most of the way in the lift box. Which is meaningless, as all it needs to do is engage enough threads to seal off the hole. As long as your replacement plug seals the hole it is fine.

To echo what Greg advised you - there is no pressure relief valve in this system other than the one in the loader control valve when it is attached. Don't ever count on the one that is supposedly in the lift box, I've never been able to determine that there is one one for sure. That's why they put a limit screw on the handle for lift control, to keep you from running it so far up that the piston pushes the seals out of the lift box. If you're concerned about the absence of a full-time PRV, you can buy an aftermarket one and install it right after the pump and with a return to the sump. Just takes a bit of plumbing and the valve.

 

[J_J]

I believe most all tractors have a relief valve in the 3pt and some have a safety valve. .

All tractors don't come with loader or loader valves, so they have to have a relief valve as they all have a 3pt system.

 

[NorTracNY]

OK, I'm somewhat at a loss. Either I don't have the terminology or there is no quick connect. on these hoses other than what connect below the joystick for the FEL. I unscrewed the fitting just to the right of 26 in the picture.
http://johnstractor.homestead.com/files/HydSteering.jpg
I put the hose down toward a bucket and turned the engine over. I never got fluid to come out and stopped. I am getting the impression from several comments that I could damage the gear pump (if I haven't already) if I ran it too long dry. I tried 2 times about 10 seconds each.

I then removed the gear pump. After lots of cleaning, I too it apart and see nothing wrong except the end of it that connects to the engine appears pretty marked up. I'm referring to the lowest part of the bottom picture here.

HydPumpDisassembled

Here are the pictures of mine.

 

[Affordable]

Your pump will need to be replaced, you also need to look at the pump driver, the part that the pump shaft goes into it may be damaged also.If it is and you don't replace it also you can damage the new pump,send me a pic and I can confirm the condition for you
tommy@affordabletractorsalesco.com

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[greg_g]

I then removed the gear pump. After lots of cleaning, I too it apart and see nothing wrong except the end of it that connects to the engine appears pretty marked up.

That "end" is the pump drive tang, and it's damaged beyond repair. The pump has been fatally dead-headed. The drive tang fits into a slot in the drive gear. The engine is turning the gear, but the gear is just spinning around the pump tang. Pump's not pumping. Take a look at the slot in the drive gear too, it should have perfectly square corners. If it's rounded (or rounding) out, it should be replaced as well.

//greg//

 

[NorTracNY]

OK, thanks for the help. I was afraid that was the case. How tough is it going to be to get the drive gear appart if that is also damaged? I'll take pictures tonight. Also, any underlying cause of this that I should be examining closer?

 

[greg_g]

I've been lucky with 4 Chinese tractors never to have fatally deadheaded a pump. So I can't relate any personal experience replacing the driving gear. But that's a bridge you don't even know if you have to cross yet.

Underlying cause is always the same, impeded fluid flow. The engine continues to turn the pump, but - since fluid has nowhere to go - the pressure builds to a fatal level. Either the tang gives up the ghost, or the seals blow - sometimes both. In the Jinma 200 series, the most common reason is inadvertent separation of the QD at the pigtail that comes off the pump. It's strongly recommended to either replace the QD with something more reliable, or to strap the two halves together with a pair of heavy duty zip ties.

//greg//

 

[timinsanborn]

you don`t have a quick disconnect after the pump. your pump output hose goes directly into the flow divider valve or priorty valve depending on your terminology. your quick disconnects are after the priorty valve,that puts the FEL hydraulics in series with the 3 point.

 

[Affordable]

We have the complete assembly or just the pump driver.If you get just the driver you will have to press 2- different bearings and a gear off/on

Here is a pic


Tommy
Affordable Tractor Sales co
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[NorTracNY]

Here's the picture of mine. I'll give you a call tomorrow to order the parts. How difficult will this be for me to install? Is it just unbolting the 5 bolts in the picture?

I'm still not sure how this happened. I've never had a hose get disconnected that I'm aware of. Anything else I should be checking on this tractor?