Hydraulic fluid coming from breather tube

[john_t]

2003 Jinma 284, Z20 FEL:

My hydraulic sump is not overfilled, but after about 20 minutes of working, hydraulic fluid is coming out of the breather tube. (behind my seat)
First I thought maybe it was overfilled, but that is not the case. In fact it will continue to spill out till my hydraulics and steering barely work.
It's somewhat foamy as it comes out but I don't know if that would cause me to lose so much fluid.
I am using Coastal brand 303 tractor fluid with "foam suppression" according to the label.
Any help ??
THanks, John

 

[DwayneB]

2003 Jinma 284, Z20 FEL:

My hydraulic sump is not overfilled, but after about 20 minutes of working, hydraulic fluid is coming out of the breather tube. (behind my seat)
First I thought maybe it was overfilled, but that is not the case. In fact it will continue to spill out till my hydraulics and steering barely work.
It's somewhat foamy as it comes out but I don't know if that would cause me to lose so much fluid.
I am using Coastal brand 303 tractor fluid with "foam suppression" according to the label.
Any help ??
THanks, John

What you are describing is usually indicative of a leak on the suction side someplace. A little bit of air goes long way. That's where I'd start. I'd bet you have air entering the system some how. Either a fitting or an o-ring.

Left to it's devices having air bubbles in the fluid will cause cavitation in the pump and erode the working parts.

 

[greg_g]

I am using Coastal brand 303 tractor fluid

Wrong stuff. That's UTF - Universal Tractor Fluid. It's intended for tractors that have a common sump for both hydraulics and transmission/differential. Speaking quite generally, UTF is too thin for Jinma gears and too thick for Jinma hydraulics.

Your Jinma will work better and last longer with gear oil in the tranny/diffs (typically 80W90 or 85W140) and hydraulic fluid in the hydraulic sump (typically AW32 or AW46). That said - considering you're not overfilled - foaming is indicative of an air leak somewhere in the circuit.

//greg//

 

[Wayne County Hose]

Your Coastal 303 is AW-65 hydraulic oil with tranny additives. I have the data sheet in front of me as I carry the Coastal brand. The additives won't hurt anything in your system, if anything, it's better than straight hydraulic oil. I don't know how the thickness will affect your Jinma, probably depends more on climate and application than anything else. If it can run the hydraulics in all the tractors that take tractor fluid, it should be okay in yours.

The prior posts sound correct, check your suction lines. Could also be a bad pump. Is the fluid hot? If so, could be something else.

If the steering will barely work, the steering pump suction line and pump circuit is a good place to start. I am not familiar with the Jinma line, so I don't know if there is a separate steering pump or not, but I'd start wherever the steering pressure is made.

 

[RonMar]

Your Coastal 303 is AW-65 hydraulic oil with tranny additives. I have the data sheet in front of me as I carry the Coastal brand. The additives won't hurt anything in your system, if anything, it's better than straight hydraulic oil. I don't know how the thickness will affect your Jinma, probably depends more on climate and application than anything else. If it can run the hydraulics in all the tractors that take tractor fluid, it should be okay in yours.

The prior posts sound correct, check your suction lines. Could also be a bad pump. Is the fluid hot? If so, could be something else.

If the steering will barely work, the steering pump suction line and pump circuit is a good place to start. I am not familiar with the Jinma line, so I don't know if there is a separate steering pump or not, but I'd start wherever the steering pressure is made.

The 200 series Jinma uses a common pump and a flow diverter for the steering valve/pump.

The OP's problem sounds like air ingestion to me also, and it is probably compounded by the use of UTF instead of something thinner like AW-32, especially if it is cold out. The thicker the fluid the harder it is to suck down that suction line so the greater the vacume the line comes under.

On that year model, there is probably a union/coupling on the suction line on top of the sump, right under the seat that allows you to easilly remove the strainer from the sump. That is the first place I would look. I think the only other seal on the line is where it meets the pump with I believe a flange and "O" ring. IF those are good, then it is possibly a pump seal or a crack in the pump housing...

I would reccomend you flush it and fill the hydraulic sump with AW-32, unless you are in a warm eneough climate to need AW-46...

Good Luck.

 

[Diamondpilot]

These guys are right. You are running the wrong stuff first off and you are getting air in the system somewhere. It seems to me you had some other problems or postings before so maybe something done then has changed your hydraulic system.

Chris

 

[greg_g]

If it can run the hydraulics in all the tractors that take tractor fluid, it should be okay in yours.

I've owned four Chinese tractors, so I can back this up with some actual experience. It's not ok. Matter of fact, I wouldn't be surprised at all to find that it's actually part of the problem.

//greg//

 

[Wayne County Hose]

I've owned four Chinese tractors, so I can back this up with some actual experience. It's not ok. Matter of fact, I wouldn't be surprised at all to find that it's actually part of the problem.

//greg//

This is where real world experience trumps book knowledge. Thanks for the correction guys.

It would help if people filled out their profiles so you can see their location. In the Sahara desert, it wouldn't be an issue. (Just kidding)

 

[john_t]

Help me to understand... is the problem with 303 oil the fact it is too thick?
If so, does it make a difference that I live in Central Florida? Or should just not use it for other reasons, even if I lived on the equator?
I have 80/90 gear oil in the tranny.

When I change the fluid is a simple drain and refill ok, or do I need to flush with something,,,if so, what's a good flusher?

That said, I worked on the tractor yesterday. Didn't find any obvious air leaks but I removed inlet filter, cleaned mating surfaces, replaced gasket and tightened all connections. (The steel tube has flared ends but no o-rings at either end.)
After preliminary testing it seems to be ok, but I'll know more after I work it a while.
Thanks for all the help,
John

 

[Wayne County Hose]

My opinion, and simply just a professional opinion, is that you can drain every last cent of 303 out of your machine, replace it with anything you want, and you will still have the problem. Being as you live in central Florida, I believe that the 303 will work in your machine just fine. As it has for how long now?