Breather cap leaks? (IH 330)

Sounds silly. I figured the cap is supposed to well breathe--

I've only had the tractor a year and its my first so still learning the basics.

If i drive it around the yard and lift the bucket up and down a few times we get some hydraulic oil coming out the breather cap. It's a reasonable amount. It continues when the tractor is stopped.

It sorta looks like its bubbling out-- like some oil comes out and then some air bubbles through the oil.

Someone appears to have modified my cap. Its hard to tell, but it almost looks to have been welded and brazed shut-- but there are a few pores still open in the braze. I have no idea what its supposed to look like.

About the tractor-- it has two hydraulic pumps one off the engine and one off the PTO. They are plumbed together together. I put some clamp on forks this summer and moved some logs, found the limit for lifting with the bucket + forks was about 400lbs. When doing this, no signs of leak except for the breather cap which was doing this oozing/bubbling thing.

I'm running TSC premium hydraulic oil, no additives. https://www.external_link.com/tsc/product/traveller-premium-universal-tractor-trans-hydraulic-fluid I'm running this because the levels were low/empty when i got it and needed to get my driveway clear for a snowstorm. It seemed to work well enough.

I'm curious here-- i could picture the stuff foaming up maybe, or something else pushing the fluid level up? Super confused.

Here are some photos i have handy-- of the cap and of the tractor (from last winter)-- happy to snap more photos-- just ask.

Not sure what's wrong here, but i can't see this thread in modern view. I click on it but none of the text or photos are visible.

I'm replying in classic view-- adding some photos.

For sure the cap needs to be able to breathe. The level in the tank has to go up and down as the cylinders work.

It may simply be over filled.

Or the tank may be too small.

With the loader raised all the way, and the curl cylinder fully extended, how low is the oil level in the tank? Is it so low that the pump begins to suck air? Is the return flow foamy with air?

If it is, the tank is too small, or possibly the suction screen (if equipped) is clogged or the pick up is too far off the bottom.

If the oil is frothy with air, that will raise the level and cause the overflow. Air can also get in from a leak in the suction line to the pump.

Lots of variables here, and are you sure both pumps operate the loader? Possibly the PTO pump is for another attachment, maybe it had a hoe at one time.

But, whatever is happening, the tank needs a breathable cap. The object is to let the tank breathe air in and out, but exclude dirt and water.

Want to add...

The proper fill level is with the bucket all the way down and curled up.

Fill the tank to withing an inch or so to the top, maybe a little lower if it will fully raise without sucking air.

I would be willing to bet that what you are picturing is a pipe thread reducing
bushing that someone brazed a common bolt into. Originally the bushing would have had
a small breather with pipe thread screwed into the small hole in center. The bushing
allowed one to fill the tank thru bigger hole. -------------Loren

Could you show or describe where that plug goes? You say the tractor hydraulic system and the PTO pump are
plumbed together show or explain how that is being accomplished. If that is true there needs to be some way to
keep adequate oil levels to the sump or reservoir of each system if they don’t both operate at the same level or
distance from the ground. Not that familiar with the IH utilities. On the view question. I think sometimes the YT people are working on
the system and things between the two views don’t always sync up during those times.

Phew-- OK-- you guys asked some good questions that might me re-evaluate what i have here. Let me fix a few things i said:

There are actually two hydraulic reservoirs. One under the seat, and one behind it. They appear separate.

The one under the seat connects to the rear PTO pump-- which appears to just recirculate and go nowhere. There is a quick connect that i suspect you can hook into (photo attached)

The one behind the seat connects to the front hydraulic pump that works the FEL.

The plug i showed is the breather cap for the reservoir under the seat which seems to do just about nothing. That said, I pulled one of the little plugs that i figured might be a max level plug. Nothing comes out-- run the motor, and let go of the clutch and it starts spewing foamy hydraulic fluid.

Here's the photo of the "after" of running with that plug out. It was a straight stream. Looked like a guiness being poured off a tap.

Also attaching a photo of what i think is the PTO clutch lever and a disconnect fitting under which might be an aux connection?

Water in the hydraulic oil will also foam and make "moose" then spurt out the breather. THe original breather was ~2.5 inches in dia, with much smaller thread, IIRC 3/8 pipe thread. The oil heats away moisture when operated regularly for hours. Because they are not operated for hours, they turn milky. Jim

thanks all-

So I understand it... Th breather cap is not stock by any means, and its unclear why its been brazed over-- unless the braze is just a sloppy job of making a custom breather cap. The tank level does rise when the pump is turned on, hinting at some type of foaming (since there's no pistons in the loop and the volume is constant).
If there were pistons, overfilled tank could maybe do this-- except that we see the foamed oil.

Foam could be moisture or a leak side on suction side of the pump or moisture in the fluid.

As for the what to do, the pump isn't really doing anything except for moving fluid in a loop. Turning off the PTO isn't really an option (ends up being a power draw). I'll try lowering the fluid level a little, and maybe snugging up the fittings/replacing things on the vacuum side-- or taking the darn thing off.

Its a funny setup though. And the manifold blocks for the send/return on the tank under the seat and the front pump look shiny/new same age.