TC40D annoying oil leak

[TO_Bud]

My 2000 TC40D developed an oil leak awhile back that was coming from under the seat area on top of the trans. It wasn't bad, just a drop or two for the longest time and I left a piece of plywood under the spot to catch the drips. Well....it recently developed into more than a drip or two and was beginning to coat the bottom of the trans and differential so I decided to give 'er a look to see if I could correct it. I pulled up the rubber floor mat to get a look through the inspection opening hoping it was just the plugs on the hydraulic test ports needed tightening. No luck, the ports were not the source of the leak, it was farther back by the 3 pt flow control valve, at least that was where most of the wetness was. Had the pull the right rear tire to get a look in there and of course it was wet with oil and caked with dirt (oily mud) all around the control valve. Upon closer examination it looked like a plug on the right side of the control valve had the most oil around it (see the first attachment). The plug was snug but not really tight and as I unscrewed it oil was seeping out until the very last few threads when it actually squirted out the last few ounces. The plug is adjacent to the flow control needle and seat and contains the pressure of the lift cylinder when the needle opens. I'm hoping this is indeed the source of my leak, I cleaned up the threads and added a good sealer to the plug and reinstalled. Haven't run it yet as I wanted to let the sealer cure well before I pressure it. Another problem was revealed when I pulled up the rubber floor mat, see pics 2 and 3. The steel platform was badly rusted, the paint had bubbled in numerous places and the rust was getting deep in some areas. I spent a good hour scraping and then wire wheeling the whole area to get rid of all the scale. It appears the paint did not adhere to the steel from the factory and I couldn't find any indications of primer being used. It was pretty disappointing to see and I'm glad I caught it when I did. The tractor is garage kept and even though it is 11 years old it has been out in the weather maybe 30 days total over those 11 years. If those of you with the TC series haven't looked under the mat you may want to do so, and it you have an annoying trans leak up high check out the plug.

Bud

 

[jinman]

Don't you love the quality paint job on our operator platforms? Sheesh! Mine is at least as bad as yours with huge slugs of paint peeling off the rusty bottom surface.

I'll look into your leaking metering valve and get back to you on what I find.

 

[TO_Bud]

I was knocked off my stool just about when I saw how bad the rust was. I'm assuming the plug I'm speaking of is a test port of sorts for the lifting cylinder, still waiting for the paint on the platform to dry before I test it out. I'll provide an update in a while if it is the cause.
Bud

 

[jinman]

Yep, everything I can find shows that to just be a plug. Probably for pressure testing as you mentioned. I'm really surprised that it isn't an o-ring fitting. It has the entire pressure of the lift cylinder applied at all times. The opposite side is the high pressure emergency relief valve that lifts above 3600 psi. I'm thinking a Loctite product might be the best choice to seal the threads if your sealant doesn't work.

 

[TO_Bud]

I thought Loctite as well, I had some Number 545 left over and used that. I had good results on a banjo fitting leak on my toplink cylinder some months back. It's formulated for high pressure hydraulic fittings so we will see. Got everything back together but now I can't see the plug with the tire back on, I'll have to watch for any drips the next few days.

 

[LarryD]

I've used a little digital camera to take pictures of an area I can't quite get good eyes on. I just move it around and take several pictures, the film is really cheap.:laughing:

 

[thclimer]

Bud,

Thanks for including the drawing attachment with your post. As you were describing the plugs location I was picturing it in my mind and as soon as I saw the drawing it confirmed exactly what I was thinking.

I hope your loctite does the job. Amazing like Jim said that there isn't an o-ring type seal there with the amount of pressure it can be exposed to.

Larry, good point about the camera. I've used one a few times for that very same reason, also with my vision getting poor when I look at the picture on a computer screen with the ability to zoom it makes it much clearer.

 

[TO_Bud]

Just might try that Larry. It's pretty tight though, I may not be able to get my arm up in there.

 

[nickel plate]

Sorry to hear about the oil leak-thanks for posting so the rest of us TC40 owners can now be aware of that problem. As Jim mentioned, a plug under a lot of pressure designed without a proper seal, o-ring or otherwise is not a good practice.
I have a standard model without the floor mat however there was a time back when I almost bought one-glad now that I didn't. Seems like the cause is from putting the tractor up wet/damp and the mat acted as an impervious membrane sandwiching in the moisture.

 

[TO_Bud]

Sounds about right NP. The mat is heavy dense foam underneath and at one time had a thin plastic membrane next to the steel floor. Over time the membrane has deteriorated and there is really no way of drying the area out after it gets wet.