New Holland TC29 Hydraulic Leak....Why?

[bigroccrek]

I have a 2002 New Holland TC29 tractor. Recently I have Hydro Fluid leaking from the top of the bucket control block(?). I took the cover off and cleaned everything up and tightened all connections (most all were already tight) but I still have a small leak. Seems to leak when I am using the bucket (makes sense to me??). I don't know a whole lot about hydraulics, but reading the forums about problems folks have had...makes me a little nervous to mess with it too much. Looks like it might be a pressure relief valve or port???? There used to be a New Holland dealer about 80 miles away but they went out of business so no help there. Any help/advice would be greatly appreciated......I hate things that leak!

 

[K5lwq]

I can understand why you don’t like leaks! That is a very clean tractor for 21 years old!

That is the pressure relief valve. May just need a new o-ring.

 

[ptsg]

So that's the relief valve cartridge for the loader valve. When it's out, it looks more or less like this:

As you can see, there a couple o-rings there to make the seal. There is also a couple more inside the cartridge.

Here is the complicated part, if the leak is between the cartridge and the valve body, you can simply pull the entire cartridge out to change the O-ring without worrying about messing with the relief pressure. However, if the leak comes between threaded stud that adjusts the pressure and the cartridge, then you'll need to take the entire cartridge apart, to change whatever seals are bad inside, but in the end, you'll need a pressure gauge so you can see the relief pressure back to factory specs.

If you don't feel comfortable do it, it's better to have someone familiar with hydraulics do it. Setting the relief pressure wrong (as in set with too high of a pressure) can break a lot of expensive stuff in a hurry.

 

[bigroccrek]

I can understand why you don’t like leaks! That is a very clean tractor for 21 years old!

That is the pressure relief valve. May just need a new o-ring.

Thanks for the response. You have confirmed my suspicion that it is a pressure relief valve. Thanks again!

 

[bigroccrek]

So that's the relief valve cartridge for the loader valve. When it's out, it looks more or less like this:

View attachment 786968 View attachment 786969

As you can see, there a couple o-rings there to make the seal. There is also a couple more inside the cartridge.

Here is the complicated part, if the leak is between the cartridge and the valve body, you can simply pull the entire cartridge out to change the O-ring without worrying about messing with the relief pressure. However, if the leak comes between threaded stud that adjusts the pressure and the cartridge, then you'll need to take the entire cartridge apart, to change whatever seals are bad inside, but in the end, you'll need a pressure gauge so you can see the relief pressure back to factory specs.

If you don't feel comfortable do it, it's better to have someone familiar with hydraulics do it. Setting the relief pressure wrong (as in set with too high of a pressure) can break a lot of expensive stuff in a hurry.

So that's the relief valve cartridge for the loader valve. When it's out, it looks more or less like this:

View attachment 786968 View attachment 786969

As you can see, there a couple o-rings there to make the seal. There is also a couple more inside the cartridge.

Here is the complicated part, if the leak is between the cartridge and the valve body, you can simply pull the entire cartridge out to change the O-ring without worrying about messing with the relief pressure. However, if the leak comes between threaded stud that adjusts the pressure and the cartridge, then you'll need to take the entire cartridge apart, to change whatever seals are bad inside, but in the end, you'll need a pressure gauge so you can see the relief pressure back to factory specs.

If you don't feel comfortable do it, it's better to have someone familiar with hydraulics do it. Setting the relief pressure wrong (as in set with too high of a pressure) can break a lot of expensive stuff in a hurry.

Thanks for the response, I suspected it was a pressure relief valve. It appears to be leaking in one of two places (see pics below), kind of hard to tell since I cleaned it up. I may just try snugging it up a little and see how it responds. If it still leaks I will pull it and replace the "easy" o-rings (need to find them first!). If that doesn't solve it then I will need to find a tractor repair shop and take it in. I did a little reading on replacing the pressure relief valve based on you comments and you are correct not setting the pressure correctly can have major ramifications. Not something that I have the tools or expertise to take it on (no pressure gauge or specifications). One question, is the VMD8 the correct valve for this tractor loader or was it just "as an example" Thanks again!

 

[ptsg]

Thanks for the response, I suspected it was a pressure relief valve. It appears to be leaking in one of two places (see pics below), kind of hard to tell since I cleaned it up. I may just try snugging it up a little and see how it responds. If it still leaks I will pull it and replace the "easy" o-rings (need to find them first!). If that doesn't solve it then I will need to find a tractor repair shop and take it in. I did a little reading on replacing the pressure relief valve based on you comments and you are correct not setting the pressure correctly can have major ramifications. Not something that I have the tools or expertise to take it on (no pressure gauge or specifications). One question, is the VMD8 the correct valve for this tractor loader or was it just "as an example" Thanks again!

View attachment 786982

Really hard to tell where it comes from. If it comes from the top, it will drip to the bottom and make it look like it's leaking from there. My best advice is to try to clean as best as possible, run it a while and check it to see where exactly it's coming from.

Can't quite tell on this one, but some times there is a crush washer between the top nut and the middle one, so trying to snug it up a little bit may help too.

Yes, the pictures I showed were just an example so you would have an idea of what it looks like. Should've indeed pointed that out, my bad.