Jinma 284 - 3 pt lift not working

[ctusdenny]

Denny, I am assuming #303 is a type of Universal Tractor Fluid or UTF? The system operating better when it warms up is a clue that the hydraulic fluid is too thick. UTF is too thick for this type hydraulic system. You need some simple AW-32 hydraulic fluid for this system to operate at it's best.

IF you look closely at the back of the lift box, at the toplink structure which is bolted to the back of the lift box, you may see something unusual if you look closely in the lower left corner. Disguised like one of the toplink plate mounting bolts is the hydraulic reservoir drain. It may even have a dab of red paint on it, which they do on many of the drains and fills to help you identify them from the factory... Inthe case of the hydraulic sump it helps to have the tractor parked with the front uphill(and wheels blocked) to assist in draining all the fluid out.

Got no help with tightening the leaking plug, other than you can pull off the banjo fitting when you drain the sump to changeout the UTF

DId you go ahead and remove that setscrew and the speed regulating valve completely to examine it? IF not, it is probably hiding one last secret. The pointed tip of the valve is pinned to the end of the threaded shaft with a slot so that tip can move up and down. Installed the tip hangs down at the end of the slot. When you lift the 3PH, fluid flows up against the tip, pushing it out of the way so you can get full flow to lift. When you lower the 3PH, the tip, now down in the way, restricts the exit of the fluid helping to keep a heavy impliment from slamming down. If it is screwed in a little too far, it will allow the impliment to raise, then act like a check valve and keep the impliment from lowering. Since it is now locked with hydraulic pressure, you cannot then unscrew the adjuster. The fix is to back the impliment up onto a hill or jack it up to take the weight off of the lift, and the hydraulic pressure off of the speed reg valve allowing you to unscrew it...

Thanks, Ron. I'll go,ahead and flush the system and get some AW-32 in there.

I did not inspect the valve this time. But with the system drained, I'll go through that as well.

I do,have the front loader, and it's connected to the system by some disconnects. Are you saying to do something with that when bleeding?

Denny

 

[SPIKER]

Thanks, Ron. I'll go,ahead and flush the system and get some AW-32 in there.

I did not inspect the valve this time. But with the system drained, I'll go through that as well.

I do,have the front loader, and it's connected to the system by some disconnects. Are you saying to do something with that when bleeding?

Denny

Just a FYI the 303 is OK, I us UTF in mine and only when it is below 20F do I notice a need to let it warm up some. From the factory these thing state straight 30 weight oil for the hydraulics so that is a bit heavier than 303 from memory.

If you are having leaks with the 303 then expect them to get worse with the AWE32 thinner hyd fluid.

Bleeding is not needed on pressure side of the system, simply let it idle and work the system some slowly to keep air from filling the tank with bubbles. If you rev it up and work it hard the air will form bubbles that can suck into the pump and get into a foam issue.

Intake is where bleeding is needed to keep the foam issue down, if you change pump or anything try to keep as much fluid in lines as possible.

Mark

 

[greg_g]

Yeah, JD303 spec has a viscosity equivalency to 30W engine oil. That's too thin for gears, and too thick for hydraulics. In a four season working environment, you'll likely be more satisfied with AW32 or AW46 in the hydraulics. It's a vented system, which means it's self-bleeding. But that requires that all QDs are properly connected and that the vent holes in the hydraulic fill plug are not plugged up.

//greg//

 

[ctusdenny]

Yeah, JD303 spec has a viscosity equivalency to 30W engine oil. That's too thin for gears, and too thick for hydraulics. In a four season working environment, you'll likely be more satisfied with AW32 or AW46 in the hydraulics. It's a vented system, which means it's self-bleeding. But that requires that all QDs are properly connected and that the vent holes in the hydraulic fill plug are not plugged up.

//greg//

Thanks, Greg. Appreciate the info.

 

[ctusdenny]

Yeah, JD303 spec has a viscosity equivalency to 30W engine oil. That's too thin for gears, and too thick for hydraulics. In a four season working environment, you'll likely be more satisfied with AW32 or AW46 in the hydraulics. It's a vented system, which means it's self-bleeding. But that requires that all QDs are properly connected and that the vent holes in the hydraulic fill plug are not plugged up.

//greg//

Greg...one more thing. I understand to connect the two disconnects at the FEL to assist in the "self" bleeding. What about the two rear disconnects? Do I need to make a hose up to connect those together as well?

Thanks
Denny

 

[SPIKER]

no need to make anything special, just leave the FEL hooked up as normal and run it up/down and even that is not really required to bleed the system as flow moves 100% of the time. The flow if stopped by blocking a QD the pump blows, seal or case.


Mark

 

[ctusdenny]

Yeah, JD303 spec has a viscosity equivalency to 30W engine oil. That's too thin for gears, and too thick for hydraulics. In a four season working environment, you'll likely be more satisfied with AW32 or AW46 in the hydraulics. It's a vented system, which means it's self-bleeding. But that requires that all QDs are properly connected and that the vent holes in the hydraulic fill plug are not plugged up.

//greg//

So, I went down to the local tractor company to buy some AW32 for the hydraulics. The service guy asked me what I needed it for, and I explained the situation with my current use of the #303 oil. He told me that the JD303 they carry is equivalent to 20 wt oil. He said AW32 would be higher viscosity than the 303. Further, he didn't carry AW32, so I didn't buy anything.

So now thoroughly confused, I've decided to go to another tractor sales place across town today and see what they say. If I can't find AW32 locally, what's my next option? Keep using the #303?

Denny

 

[jbrukardt]

check auto parts stores for AW32. My local Advance Auto carries a 5 gallon bucket of "Shield" brand for about 40 bucks.

Shield Economy AW 32 Hydraulic Fluid S3H025/45009: You

 

[SPIKER]

still say these are setup to run 30 weight oil without much issue it works, the 303/UTF is OK in WA cold temps are not bad (unless you are high altitude in eastern side>) then a few min warm up is all you need (should let it warm up anyhow.)

Mine has more problems with the thinner fluid in it than it did with the 303. (it is mostly all Hyd Fluid now & was UTF/303) with the thinner Hyd Fluid I have less steering and the FEL drops quick due to all the bypassing of old seals/leaks the thinner fluid flows easier. Remember from Factory they say use same fluid as you use in the engine (30 weight motor oil.)

Mark

 

[RonMar]

Check the autoparts stores, Napa and Autozone carry it, as do the farm supply stores typically...