Confused... Leaking hydraulic oil

[Yanmar Chris]

Hello Everyone , Have a leak and not sure why and how to fix it. It's on a 1979 240D . After running for awhile I have hydraulic fluid leaking out where the gear shifter is and in the back out of a small black hose that looks like it's connected to either a brake housing or the axle.
It seems like when the gear case gets warm it pushes the fluid out of the shifter and black hose in the back. I've unscrewed the dipstick to check the level and I can hear air being released.
Is there supposed to be a hose to release this pressure that's possibly clogged ? Any help would be greatly appreciated. Thanks Chris

Here are some pictures

Below is a picture of where the fluid comes out of the hose

Red arrow is the dipstick where air gets released when unscrewed. Green arrow where fluid leaks also.

 

[284 International]

The vent hose should relieve any built up pressure. I don't recall offhand where my 240D's vent tube(s) are, but the YM2000 has one on top of the rockshaft housing, number 8 in this picture.

How does the hydraulic fluid look? Is it milky? I would speculate the system is over-filled, and the expansion of the fluid as it warms simply causes it to spill out the vent and boot.

 

[J_J]

You may have a suction leak and the air bubbles is causing the fluid to expand, and force fluid out any orifice. Heat will expand the fluid also.

 

[deepNdirt]

what is the oil level when you checked it? I'm sure overfilling of the system could cause this, I see you have both a FEL as well as a back-hoe, the cylinders of these could purge quit a bit of hydraulic fluid back into the reservoir at one time and if system is too full could result in finding its way out, or does the back-hoe have it's own hydraulic pump that runs from the PTO? Incidentally mine use to leek around the shifter boot, I put double zip-tie straps around it, problem solved and as mentioned the vent tube should be at top of the housing, someone may have added the hose in attempt to extend the mess away from the tractor, But it should not have any fluid coming out, do you work the tractor on uneven terrain? perhaps this is when the fluid starts coming out the worst,

 

[Car Doc]

I think the vent for the trany is a J shaped pipe under the seat on top of the 3pt cylinder it may be plugged which may explain the pressure in the trany.

Don't know if that would cause this or not but to me it sounds like its way over filled at the least.

 

[California]

The vent ... on top of the rockshaft housing, number 8 in this picture.

And if that hose in your second photo is #49 here - then the seal behind the brake drum, that keeps oil out of the brakes, has blown out. See #62, 63 on the Transmission-Internal page.

 

[Yanmar Chris]

Thanks everyone for the input. Checked fluid level tonight. Fluid is clear , not milky and not overfilled. The backhoe has it's own pump on the pto. Checked that vent that 284 International put that link up and yes it was under the seat. Looked like an upside down J lol. I put a firm piece of wire in the vent and a whole bunch of dirt and crap came out.
The tractor was sitting out for years so maybe some insects were making it their home. Put some zip ties around the shifter boot. We'll see if that helps.
That black hose is what California had put up and it is #49 in that link.
I don't have the money or time to replace the seal at the moment. I just might put a screw or plug in that hose so I don't loose any more fluid.
I know I should not do it that way but it's a temp thing.
I usually use the tractor on level ground and I don't see any fluid coming out of the vent under the seat, it's by the shifter and the hose by the break.
Next time I run it I'll post up what happens.
Thanks to you all for the help. It's greatly appreciated