Eaton Hydro burped????

[pfrederi 17,866]

I have 8 sunstrands but only one Eaton so I am not sure what happened here.  Back on 5 November I put the 418A into storage for the winter.  Been to the shed a couple times since no issues... but yesterday when I went there was a puddle of oil under her rearend.  While I watched it dripped.  Now it hasn't been moved for two weeks. Traced it and drip came from the top by the dipstick. Pulled the stick and it spurted oil out....  We have had some wild temps lately, it was near 70 when i put her away.  A couple days ago it was down to 21...yesterday made 68.  Ideas on what happened?  Reads at the bottom of operating range on the stick now.  I am pretty sure it was at the top edge of the operating ranges when I parked her....

[squonk 41,324]

Yup it burped. Had the same sorta thing happen to me on Marvin years ago.

[lynnmor 7,354]

I had that happen a number of times.  The curl on the end of the dipstick is a vent, make sure that it hasn't been pinch shut or is clogged.  Keep the oil a bit below the maximum line may help.  I'm not positive that the venting and lower oil level is the complete answer, but so far I've not had a problem since addressing these two things.  The extreme temperature changes apparently are the cause and it may go a year or two between the burps, so time will tell.

[Ed Kennell 38,639]

I have five 1100s and never had a problem.

I must confess, I do turn em over and pat their bottoms before I put them down for a nap.

                                             

[squonk 41,324]

26 minutes ago, Ed Kennell said:

I have five 1100s and never had a problem.

I must confess, I do turn em over and pat their bottoms before I put them down for a nap.

                                             

[stevasaurus 22,863]

Does oil expand and contract with temp changes??  I did not think so.  I'm thinking air bubble from pushing??  Kind of like kitty gas...if you know what I mean.    

[lynnmor 7,354]

3 hours ago, stevasaurus said:

Does oil expand and contract with temp changes??  I did not think so.  I'm thinking air bubble from pushing??  Kind of like kitty gas...if you know what I mean.    

 

My guess is that some oil drains back to the transmission and raises the oil level just enough to reach the bottom of the fill tube, then expansion and contraction of the remaining air "pumps" the oil up the tube.

[19richie66 17,522]

I had the one in my wife’s 1054 sitting on the stand before I opened it up. Came home one day and it had a puddle under it. Wasn’t even hooked to anything. Pulled the dipstick and it burped. 

[JoeM 7,874]

Yes seen it too! I have an xi under the lean to now I seen that last week. 

Another thing that is weird.  I have a thin funnel that has ridges along the outside tube to allow air to pass out. I use it to refill the hydro transmissions. Works pretty good and can save from removing a bolt. But anyway, I can dump in 4 quarts on a change with no issue, the last half of quart will cause a burp. go figure. 

[pfrederi 17,866]

First time i have ever had this happen and she has bee in winter storage for several years now...  None of the Sunstrands have done it....Glad it is not indicative of a problem.  Thanks for the replies

[clueless 3,011]

Like some of us when we get older they may have to relieve some pressure with out being aware of it till it happens .

[Ike 75]

I had the same issue on one of my 520’s.  It never happened before I changed the hydro oil.  I tried everything that this forum suggested.  Still would occasionally burp.  Finally, I drained a little out of crankcase and it never happened again.  Hydro works great.  I have three other Eaton 11’s and never had it happen on any of them.