Really Weird

[JATO_RaT]

I have a International 454D (with Lightning Shift, whew). When I check the hydraulic oil level via a dip stick next to the left heel of the operator, I get two readings. My first reading, taken in the morning after the tractor has sat overnight, shows no hydraulic oil, not a drop on the stick. So, being concerned, I put it back in the same exact hole, don't start the engine, just put it back, easily, and when I pull it out, it now shows the level right where it is supposed to be, about and 1.5" up the stick. I'm not making this up, I think I have a magic tractor. How does it do this? Any ideas, Bird, Del, Harv, Chalkley, Rowski, Paccorti, heck JimBin in Michigan (aka Mighty TC18), anybody, Rat...

 

[Bird]

Sorry, Rat, I don't know how that could happen unless the dipstick wasn't all the way in the first time.

Bird

 

[Harv]

Rat -

Let me start by saying I don't have a clue about such things, but I love to make up answers anyway (got me through college, didn't it? /w3tcompact/icons/wink.gif).

Partial shot-in-the-dark theory -- for some reason an air pocket forms around the bottom of your dipstick after the oil has been at rest for a period of hours. When you pull out the the dipstick, the pressure causing the air pocket is released and the pocket collapses. When you re-insert the dipstick, the fluid is back where it belongs.

What would cause such an air pocket? Well, you see, as the fluid cools, air is sucked in, and, uh, you know, uh ... I'll let somebody else make up that part of the story. /w3tcompact/icons/crazy.gif

 

[Bird]

Hey, Harv, that's a better answer than I could come up with./w3tcompact/icons/laugh.gif And it could very well be right. Unless of course it really is magic./w3tcompact/icons/wink.gif

Bird

 

[Anonymous Poster]

harv is right on. most dipsticks on constuction equipment are the same way we always wipe the stick and check it again for a true reading

 

[DaveNH]

Harv,

I think you're on the right track here, but I think it is pressure in the tube. When the engine/pump is working, the level of oil inside the block will be lower. Shutting the machine off, traps air inside the tube. Now this air is under pressure as the oil drains and returns back to the block. Pulling the dip stick, releases the pressure.
All this is based upon the ASSUMPTION that the tube and dip stick are the same length.
(take a straw, seal it on one end, put in glass seal end up, fill glass with water, how much water is in the straw?, then unseal the straw and check again)

We're all in this together!<P ID="edit"><FONT SIZE=-1>Edited by DaveNH on 02/17/01 08:15 PM (server time).</FONT></P>

 

[Von]

If this is the case, then check the breather tube (if it has one on the trans,) it may be blocked. I had this happen on my kubota when I first got it. A mud wasp thought the tube would make a good nest and blocked the tube. The tractor sat outside on the dealers lot and thats where it happened. As soon as it got up to temp it caused the hydro oil to blow out the dip stick. This is not what you are experinecing, but if the tube is blocked (if you have a vent) it would cause the air pocket.

 

[JATO_RaT]

Harv, very good, I actually had considered that a slight increase in pressure in the dip stick tube area might preclude oil from entering that area that the stick resides. Maybe, it makes sense since oil magically appears after the stick is reinserted which by this time has allowed differences in pressure to equalize via the dip hole. Even though the entire case is vented under the seat, a pressure difference possibly continues to exist, dang, I thought I had a magic tractor, Rat...

 

[Harv]

<font color=blue>dang, I thought I had a magic tractor</font color=blue>

If you have a magician in the seat, any tractor can be magic. /w3tcompact/icons/wink.gif

 

[caddison]

Rat,

Next time you check the fluid, instead of pulling the dipstick out all the way simply pull it up past the seal, give it a few seconds and re-insert and see if the fluid appears. That might enforce the pressure theory. Just a thought. You may want to check all the vents and make sure they are open.