IH 3400A pressure in transmission/transaxle

[Chad Duncan]

Hello everybody,
I have a small amount of oil being pushed up and out of the top of my transmission. There is a pin that comes through the top of the case and a small amount of oil comes up through it. I have found what I believe is the vent/breather cap but it doesn't work as I would expect it to. This breather seems to work in the opposite direction that I would expect it to. It seems to be set up to keep the case from developing a vacuum while keeping any pressure inside. That is to say I can't blow through it, but I can fairly easily suck through it.
Is this the way it is supposed to work? is there a second breather somewhere working in the opposite direction? Can I replace this with something that breathes in both directions like a common valve cover breather?

 

[Chad Duncan]

With lung power I can overcome the vacuum side but it takes air compressor power to overcome the pressure side. Does this simply sound like a failed breather valve?

 

[Delmer]

Could you post a picture of the valve? I can't think of anything like what you're describing, and unfortunately there aren't the IH experts on here like there are for Cat, Case, or Deere.

 

[Chad Duncan]

This is the item that I am calling a breather. maybe 'pressure relief valve' would be a batter name.
http://img.photobucket.com/albums/v645/Evilhorde/Mobile Uploads/20160323_181310.jpg
I wish I could post a picture but all I get are error messages. The link is good enough for my browser but not good enough for the forum. sorry.

 

[Delmer]

Sorry, that's a new one to me. Any chance you can take it apart to reverse engineer it? figure out if there's a valve in there that's working or a filter that's plugged?

 

[Tinkerer]

The one in your photo may not be the correct one. Take a look at # 17 & 18 in the parts manual here ---->http://partstore.casece.com/us/parts-search.html#epc::mr67205ar233104bi2319955-17

 

[Delmer]

Your picture looks close enough to the case diagram to me, seeing as there are half a dozen different part numbers for the same breather.

I missed the most simplest question at the end of your first post. Yes, you can replace this with any breather that fits, or run a hose up to a higher, cleaner, dryer place and put a breather there.

 

[Chad Duncan]

I missed the most simplest question at the end of your first post. Yes, you can replace this with any breather that fits, or run a hose up to a higher, cleaner, dryer place and put a breather there.

Sounds like a plan to me.
Can you think of any possible reason why the case might require some small amount of pressure in it? (before I put on a breather that flows easily in both directions)
And if I can't get a replacement this weekend, do you foresee any problems with using a clean rag as the breather? I only wonder because it drives me mental to see the oil coming out and also running without the suspected bad breather will help me to determine if the breather is the cause of the leak. I don't expect a lot of use this weekend but I do need to load up a pickup truck with manure.
Thanks for the help guys.

 

[Delmer]

Yes, some newer machines pressurize hydraulic tanks to reduce cavitation in pumps. I doubt this was designed that way, but you'd have to take an original breather/valve apart to know.

I'd run a hose up to a cleaner spot, and wrap a rag around the end of the hose. A rag stuck in the hole is asking for stuff to fall in.

 

[Chad Duncan]

Yes, some newer machines pressurize hydraulic tanks to reduce cavitation in pumps. I doubt this was designed that way, but you'd have to take an original breather/valve apart .

I can't take apart this breather without destroying it (if it's even the right one). I'll just run without it (using a rag ) and see what happens. If it solves my problems them I'll replace the breather. If there is no change, I'll put this one back.

 

[Delmer]

Is there a rivet on the top that you can grind off? or is that outer cover crimped/rolled in at the bottom? either way you can grind it off if you want.

 

[Juskatla]

Chad, You can get various sizes of hydraulic breathers at Princess Auto in Langford. Check out their web site. You may also find them at your local hydraulics place. I deal with Cowichan Hydraulics in Campbell River and they have this type that screws into the reservoir. I don't think there should be any pressure built up or you will end up with leaks at the seals.

 

[Chad Duncan]

I ran a rag breather yesterday while I moved some manure around the farm here and removing the old breather seems to have completely solved the leak. Of course all that poking around has led to the discovery of even more leaks but I don't believe that they are related to this breather issue.