Jimna 204 Hydraulic Fluid Foaming

[Weaklink]

My dad has a Jinma 204. The hydraulic oil is foaming and coming out the fill cap. He thinks it's sucking air at the intake junction. He took it apart once, and said the flange had an o-ring, but there was no inner retaining ridge on the flange to prevent the o-ring from being sucked into the line.

Is there a special o-ring or plastic retainer in this joint? Where can I find a schematic? I have searched but no luck.

Thanks,

James

 

[Bob Rooks]

He took it apart once, and said the flange had an o-ring, but there was no inner retaining ridge on the flange to prevent the o-ring from being sucked into the line.

If there is no capture for an O-ring in either the pump body or the flange, then it doesn't require an O-ring - it uses a gasket.

 

[Affordable]

The groove is in the fitting, send me a pic of the fitting and I can tell you 100 %,all the ones I have seen use a O-ring

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

 

[RonMar]

Also, don't forget to check the pipe union fitting in the suction line back under the seat. That is another good place for an air leak...

 

[Bob Rooks]

What kind of oil is being used in it?

 

[Weaklink]

Thanks for the replies. I live in NC, but my father lives in WA. He is 74 and was a Caterpillar mechanic for 40+ years. He could fix anything under the sun, and people all over the county still seek his help. As such, he does not relish working on his own little-used tractor, and does not know how to use a computer, so I thought I would just quickly look-up the union on an exploded view, like I do only any Chevy/Ford/Honda/etc. Little did I know that these illustrations are not widely available.

The tractor operates fine. The FEL & 3-point are operating, just foaming the oil. My dad only uses it a couple times a year. He said the last time he used it, the hydraulics were not working, but we added fluid, fired it up, and completed a 20 minute rip job in the yard, albeit with some foaming overflow.

He vaguely mentioned that he recently rebuilt the pump, due to foaming. The suction fitting to the pump did have an O-ring (as expected) but the groove had no inner lip to retain the ring from being suck into the line. I thought maybe the exploded view would give insight, or a new part number, or the part number for the O-ring, etc.

This will be my project upon my next visit. I have no other details. I think he bought it used, but not sure if he replaced the fluids, flushed, filter, age, etc. I'll tear into it my next visit. At least now I have some contacts for parts and advice.


Thanks,

 

[Bob Rooks]

If your Dad is a retired Cat mechanic of 40 years in Washington state, I might know him. I worked for NC back in the day.
If he lives in the Greater Seattle area I might be able to swing by and take a peek at it. I'm still active. :laughing:

 

[greg_g]

Check the suction line at the sump too, it could be sucking air anywhere between the sump and the pump. Another thing, do not overfill the sump. The correct way to check fluids on Asian equipment with threaded dipsticks is to set the dipstick on the hole. Do not screw it back in for your level check. Many first time Chinese tractor users - unaware of that basic precept - end up with wet rear ends, with or without suction leaks.

//greg//