TC 40 hydraulic oil backing into crank case

[parcrotcart]

Jinman, thanks for the info. Got it down and will try to put it back together soon. Expensive little o-ring pack! I hope there isn't anything that caused it to fail that causes this one to fail!!!

 

[parcrotcart]

Well just my luck. I installed the seal kit and started up the tractor after changing oil and adding Hydraulic fluid. I raised the FEL and 3 point a few times to get the air out and about the time I finished that, here comes the oil out of the top of the engine again. Found a small split in the new seal(it was split in the middle, not torn on the edge) and had my mechanic sweet talk the parts house into selling just the seal for $35.(these are New Holland parts, not aftermarket) Put this one together on a table with plenty of lube, then installed it and same thing! About the time it took to raise the FEL and 3 point, here comes the oil out of top of the engine again. Any ideas? Is there any other way that hydraulic oil could be getting in the engine. The shaft looks great, not scratches etc..... and its putting out about a cup every 4 seconds!!!!!

 

[jinman]

Looking at the parts list, all the individual seals are sold separately. Nobody is doing you any favors by selling you a single seal. That's the way they are listed on New Holland's parts catalog. Your pricing was right for the shaft seal, but you should not have to "sweet talk" anyone to buy an individual seal.

When you put the whole seal kit in, did you replace all the internal seals and backup rings? Every single one of these I've heard of where the shaft seal only is replaced will soon fail again like yours. That indicates the internals seals are leaking. That shaft seal is not a pressure seal. If there is an internal leak, it will blow out.

I don't want to assume anything about your level of expertise, but I sure have some doubts about my own level and learning curve. When my pump was leaking, I took the whole pump into my dealer and asked them to do the seal kit. I figured they fix lots of these and know what they are doing. It turns out that they only replaced the needed seals and the labor time was short. My whole pump was fixed for less than $200. It has performed flawlessly since. If you aren't sure you know exactly what you are doing, I might suggest that this could be a cheaper fix with a happier outcome. I just want you to get your tractor fixed whether you do the job or someone else. I think that's what you want too and to stop the drain on your wallet.

 

[parcrotcart]

i'm not claiming to be a mechanic! Just trying to save a few bucks. I put the $200 kit in first, nad after it leaked, we found a small split in the NEW shaft seal. So we put another one in and it to is leaking. Are you saying that inside the pump where the impellors are, that there are more seals? I hope so, cause I'm stumped. Should I take the whole pump in to the dealer and let them tear the pump itself apart?

 

[parcrotcart]

Plus, the split we found in the new seal was about a sixteenth inch long and I can't see how that much fluid was going out through that little hole.(a cup every 4 or 5 seconds!) At least thats how much was coming out the top of the engine!

 

[jinman]

Plus, the split we found in the new seal was about a sixteenth inch long and I can't see how that much fluid was going out through that little hole.(a cup every 4 or 5 seconds!) At least thats how much was coming out the top of the engine!

If you compute how much oil the pump is producing at normal RPM, it's about 2.6 cups per second based on 9.8 gpm capacity. When the system is pressurized under use like using the 3PH or FEL, the system pressure of 2500 psi can push lots of oil through a tiny hole. For my hydraulic remotes, I have 0.030" orifices inline so I can control the speed of hydraulic cylinders. An uncontrolled hole 1/16" is equal to an orifice size of 0.062" or about twice the size of the orifices in my hydraulic lines. So, my answer is yes, you can easily push a cup every 4-5 seconds out a tiny hole like that.

Below, I've included a photo of my pump with a blown outer seal. It's larger than 1/16", but the outer seal is not a pressure seal as I said before. The entire pump inner seals are shown in the illustration. Parts #10 thru #15 are supposed to be included in the repair kit #17. The two big seals are item #11. Items #10 are bushing seals and item #13 is the backup ring. Item #7 is the gear pump and item #6 is the driving gear. So yes, the wear blocks (items #8&9) must be removed and all the seal components replaced.

The Repair Manual says to inspect all components for excess wear and scoring after disassembly. All these steps and what to look for are why I decided to have my dealer's shop rebuild my pump. I figured they knew just what to look for and all the tricks to make a successful job. I know you are trying to save money, so was I. I did all the pump removal and re-installation, but figured the cheapest way to get a good seal job was to let somebody else do the job. I don't mean to lecture you, but rather just tell you where my head was when I fixed my pump. I understand your frustration now, but that outer seal blowing is evidence that something is wrong with the internal seals. You'll have to tear it down again. Sorry. . .

EDIT: Of course, you could also have a problem with the power steering pump. Do you have the pump with the separate reservoir or does your PS pump draw fluid from the main reservoir? If you have a separate reservoir, checking the fluid level there will verify that the PS pump is fine. Those two pumps are the only source of hydraulic oil into the engine. Also, the hydraulic oil won't hurt your engine as long as you drain it down to normal levels. Multi-G 134 is a multi-grade oil/lubricant. I would not run it instead of engine oil for extended times, but until you know for sure your pump is going to hold, I'd just drain the excess oil down to normal levels in the engine and run it to test. I WOULD NOT change engine oil and filter every time I was testing. Save that job until you are sure your main pump seals are holding.

 

[parcrotcart]

Well just back form the dealership in Baton Rouge. The shop guy said I need a new pump and that they wouldn't have even sold me a kit if I would have brought it in to them. He slid the gears out and felt up in the pump(#'s 8 and 9 on the drawing) and said feel that. There was about a quarter inch of barely scuffed area on the surface of the pieces that the gears rotate inside of. He said the pump goes into "bypass" when it's like this and thats whats blowing the seal. Only way to fix it is with a $703 new pump!

 

[jinman]

That's a real bummer. How many hours are on your tractor? Have you ever let the hydraulic fluid run out or the pump run dry? In my opinion, the pump should not wear like that except for excessive hours or running dry. With that much wear, you'd expect to see a lot of particles in your main hydraulic filter if you cut it apart or in the bottom of your reservoir. That sure is excessive wear. Have your hydraulics been acting weak before the failure? I have 1700 hours on my tractor and my hydraulic pump only needed seals. This puts you in a tough position because you don't have a known good pump to compare. You have to accept that your pump's wear is excessive. I'm not saying it isn't, but I am saying it had to be caused by something abnormal.

 

[parcrotcart]

I got it with 500 hours on it and now I have 620 hours. It's a 2005 model that I got a couple years ago. Most of the hours I put on it were idling. A little bush hogging and mostly carrying things around the yard with the FEL. I thought it was getting slow and I'd have to rev it up a little to pick up the FEL. But the H. fluid level was OK a few days before it started coming out of the top of the engine. Seems like you could just replace the wear plates, but this guy said it,s shot. Interesting, because Messics(parts place) emailed me a few weeks ago and said they would sell me the seal kit, but that their mechanic said I needed a new pump! How the heck did he know!!!!! Or is it just to sell big ticket items? I don't know...,....

 

[RickB]

. Interesting, because Messics(parts place) emailed me a few weeks ago and said they would sell me the seal kit, but that their mechanic said I needed a new pump! How the heck did he know!!!!! Or is it just to sell big ticket items? I don't know...,....

Please explain how advising AGAINST a $200 seal kit that will not preclude the necessary $700 pump purchase amounts to overselling. Seems to me following that advise would have saved you a minimum of $235.
Fact is, the vast majority of shaft seal failures are caused by worn out pump shafts and bushings/end plates.