TC40 Hydraulic Leak

[twabscs]

Hi All,

We'll after 76 hours on my TC40D, it looks like I have my first real problem. Mowed two weeks ago and checked the hydro fluid afterwards and it was really low. Added about a gallon of fluid and said to myself, Hmmm, better watch it carefully. Today, mowed for awhile and noticed that it was running hotter than normal. Pulled into the barn, let it idle awhile, and decided to look underneath. Oouch! Hydro fluid seem to cover the whole bottom area of the tractor. I've attached some pictures with some hopes that you guys might have some ideas on where the leak might be.

I'll call the dealer on Monday and have him pick the tractor up, but just wanted let everyone know that they need to check that hyrdo fluid often. It can leak in areas that you would never see, especially if you park you tractor on dirt, as I do, as leaks don't show up well there.

Ironically, stopped by the dealer this morning to look at the new TN75DA that he has on the lot and asked him about the 50 hour service that they recently did. He mentioned that they DO NOT change the hydro fluid during the 50. I thought that was a bit strange as it seems like you all change the hydro fluid at 50 hours.

Oh well, hope it isn't anything very serious.

First pic shows how the fluid is pooling and dripping off. It kept dripping at a good pace even after I shut her down.

 

[twabscs]

Picture 2 shows where I think the majority of the fluid was coming from.

 

[twabscs]

Picture 3 with a wide view of the area showing fluid everywhere.

 

[jinman]

Tom, all your pictures are of the transmission/mid area of the tactor. Is there any fluid toward the front of the tractor or on the bottom of the engine? If it's from the transmission area only, you probably have those leaky pressure test ports on top of the hydrostatic transmission that several other people have. It seems they check the hydraulic pressure at the factory, but many times they don't get those connections tight enough.

Of course, I'm just guessing, but several folks have had a similar problem. /forums/images/graemlins/confused.gif

 

[twabscs]

Hi Jim,

Thanks for the reply. Yes, all of the fluid was toward the back of the tractor. Engine area seemed fine. I'll mention this to the dealer. Are there previous threads on this that would indicate it's a common problem? I'll do some searches to see what I can find.

Thanks,

 

[joes_427_vette]

Jinman;
Where are those hydro ports located you speak of? Mine doesn't leak but...... the bucket rams and the 3 remotes will leak down while sitting. I can hear a slight sound like an air leak at times that comes from the hydro filter area by the starter. I thought I had a split in a steel line but I can't find a leak and the fluid level is fine. Guess I will have to break down and buy a service manual. Thanks in advance..

 

[twabscs]

The leak does sound like the problem TMAC had with his TC45D.

Minor Hydr Fluid Leak hopefully!

 

[twabscs]

Joe, here's a thread that might help:

Is this noise normal?

 

[spencer200]

The rubber hose that you have in your picture tend to split and leak. The clamps also loosen and leak on some of the class threes for some reason. I do not know if that is your problem but I have seen it many times.

 

[jinman]

Joe and Tom, I think you already found TMAC's post about his leak problems. There was another post that addressed the same area I'm describing, but I don't remember where it is. Actually TMAC had a leak in his joystick plumbing too.

The point on top of the transmission is the test port for checking the relief pressure of the HST transmission. There are two ports: one forward, one reverse. When the test adapter is removed these ports get capped with a plug. That plug is exposed to some of the highest pressures on your tractor. The HST relief pressure is 5,000 psi. The HST pump has twice as much pressure as the 3PH and loader hydraulics off the engine driven pump. That's why those ports are "suspect" for leaks that seem to be coming off the top of the transmission.

I've included a picture of the area where the ports are located. I took this picture when I was repairing my broken HST pedals, so it's not the best picture. I included an inset from the Repair Manual for a better view. These ports can be accessed thru a panel located beneath the rubber floor mat (just below the NH emblem), but the floor mat removal is a pretty big job in itself. Probably the best way to check the location of the leaks is to use some purple cleaner (like SuperClean) and get all the excess oil off your tranny. Then operate your tractor and cycle the hydraulics (loader & 3PH) a few times to see if the leak develops. If not, put the transmission in High/Rabbit and hold your brake while pressing the forward and reverse treadle. This will ensure the relief valves unseat and maximum pressure is felt at the suspected ports. Look for the leak again and see if the oil is coming off the top of the tractor. By not moving the tractor while you are doing this check, the oil should not get all over the bottom of your tractor and you can see where it's coming from.

Joe, on your "hissing tractor," I think there are several things that could be causing your sound, but if there is no fluid leakage, none of them are anything to worry about. If your tractor is idling, that hydrostatic filter has a ball checkvalve that is noisy when idling. If the tractor is shut down, it could just be pressure slowly equalizing on both sides of the valve. You often hear similar noise in the cooling system too. Again, if there are no visible leaks you don't really have a problem in my estimation. Any leak, no matter how tiny, will rapidly grow a "beard" from dust. It's impossible to keep quick disconnects clean even with their small leakage unless you cover them with plastic bags to keep the dust away.

Tom, you can spend a lot of time searching for the leak, but if your dealer is going to service the tractor soon, you might just wait for him to find the leak and you can do the cleanup afterwards. Maybe you will get lucky and he will clean your tractor for you. /forums/images/graemlins/cool.gif