Heavy oil leak – possible it's the filter?

[agbegin]

Hey all, new to the forum, and new to tractors in general. I picked up a used 2006 New Holland TC26DA this summer.

It has been working well, but yesterday it started leaking hydraulic oil from the rear quite heavily (left a trail, and when I stopped it pooled up).

The leak seems to be dripping down from the smaller filter itself (not dripping from the casing or hoses). Wondering (hoping) that it may be possible the filter seal is bad, maybe from dry rot or something? Wondering if anybody has seen this happen? Might a rotted hydraulic filter gasket cause a heavy leak?

And secondly, wondering if I can unscrew the filter without dumping a ton more oil, so I could check it out?

I do need to replace the hydraulic oil in the whole thing, the oil is milky looking... I just would like to locate the leak first so I don't waste time and money trying to change out the oil only to need more maintenance later.

Lastly, it does look like the rear transmission casing has been welded in the past (see photos). Praying that it was a strong repair and that it's not the cause of the latest leak. (there is little to no oil coming from the casing, it seems to be dripping down the filter)

Any tips/guidance to diagnose the leak is much appreciated.

 

[Rockbadchild]

yes a broken seal is a possibility and you are good to remove the filters it won't drain the oil, oil is pump into those filters... the only one you can't do that with is the sump filter, that one will drain the whole systems.

 

[CloverKnollFarms]

The first thing that stands out to me is the appearance of a lot of welding on that rear casting… am I seeing that right? Looks really suspect

Ive never seen a filter gasket go bad, but I am concerned about the seemingly ugly repair in that same area being the vector

 

[agbegin]

Thank you @Rockbadchild! I will check it out today, stay tuned...

 

[agbegin]

The first thing that stands out to me is the appearance of a lot of welding on that rear casting… am I seeing that right? Looks really suspect

Yes. I did not see it when I bought it (shame on me). Bought from a neighbor around the corner and seller did not disclose either. Hoping it's not the cause of this issue as I'm sure if that's the root of the issue, I'll be doubling the price I pay for the tractor very quickly

 

[LouNY]

I have seen filter gaskets let go before. There is a possibility of a misaligned (warped) gasket surface also.

 

[CloverKnollFarms]

Yes. I did not see it when I bought it (shame on me). Bought from a neighbor around the corner and seller did not disclose either. Hoping it's not the cause of this issue as I'm sure if that's the root of the issue, I'll be doubling the price I pay for the tractor very quickly

Hope it’s a simple fix. I’m worried about a stress fracture that has been growing over time. Also super curious about what could crack that rear casting!

 

[agbegin]

Hope it’s a simple fix. I’m worried about a stress fracture that has been growing over time. Also super curious about what could crack that rear casting!

Thanks for chiming in and for the kind words, am hoping the same! Yea, I actually visited the previous owner yesterday to pick up the owner's manual, and asked him if he had done any major repair. He mentioned something about letting a friend borrow it in the past and that friend "touching it up"... I did not push the issue as I'd rather not get into a confrontation unnecessarily... but I am curious to get a closer look at those welds and am praying they are unrelated to the current leak.

I'll update this thread once I get that filter off to share what I find

 

[nyone]

Yes. I did not see it when I bought it (shame on me). Bought from a neighbor around the corner and seller did not disclose either. Hoping it's not the cause of this issue as I'm sure if that's the root of the issue, I'll be doubling the price I pay for the tractor very quickly

You didnt look under it before you bought it?

 

[agbegin]

You didnt look under it before you bought it?

I looked, but definitely not well enough (I know, I know look at that thing, should be obvious). Spent more time under the hood than the rear. Rookie mistake. I also drove it and tested out all the functions which were working as expected. Live and learn. (hope to avoid learning the hard way, but ready for it )