Can't fix Leak in my loader Bucket cylinder

[M_Brown]

One of my bucket cylinders is leaking. I was using my tooth bar with the teeth straight down, just touching the ground clearing some brush when I hit a root and one of the bucket cylinders blew. I was moving forward slowly so the rod was moving out of the cylinder when it happened.A cloud of Hydraulic fluid burst from the cylinder. I believe I blew it with an impulse. Ok, so I got 2 seal kits from my kubota dealer and replace the seals on both bucket cylinders. Thinking all was well I fired it up and to my surprise the leak was still there. The other cylinder is still fine and does not leak so i believe i did not damage the new seals when i installed the head gland. The leak is not from the front wiper or rod seal it is coming from between the head gland and the cylinder barrel where they meet. The head gland is pushed in the end of the barrel and seals with an o-ring and is held in place by a retaining wire installed through a hole. I don't know maybe I damaged the seal but if that was the case why is it the same cylinder that leaks, was I just lucky on the other one. I am thinking that I have a cracked head gland or cylinder barrel. Does this sound possible? Has anyone ever had this problem that was not fixed with a new seal kit. I put in a couple of pictures of the end of the cylinder. The arrow points to the hole where the retaining wire is installed and the fluid leaks from there or around the space between the head gland or barrel.

 

[M_Brown]

I finished replacing the o-ring seal a second time and it still leaks like before. I checked the end of the barrel for signs of something that would damage the o-ring before i put it in and even touched it up with emery cloth for good measure just in case. It all appears ok. I was very gentle when i put the head gland back in, and it seemed to go in smoothly. When I removed the gland before replacing it a second time the o-ring had alot of damage after removal, but i think i'm getting the damage when it passes the retainer slot upon removal. I was thinking of swapping the gland to the other side but I risk damaging the seals everytime I take it apart and don't really want to have to replace parts on the other cylinder i just renewed the seals on. what would you guys do? maybe I just need to take the cylinder in and have it looked at before i dump to much money into this problem. I seem to be getting nowhere. Thanks

 

[M_Brown]

I decided to repost my problem in this forum because it is more Appropriate.I have been working on this for 2 days trying everything i can think of. I even tried a fourth o-ring that is thicker, ( 3mm instead of 2.5mm) but of smaller o.d. when stretched onto the gland it stood slightly more proud of the gland surface and I was still able to get it to slide into the barrel making an extra tight fit. I then removed it and it still looked ok. so I assembled it and tried it and it still leaked. AAhhh. I also swapped the fitting on the gland with the one from the other side just in case it was leaking and running down from the top of the cylinder and appearing to come from the slot between the gland and the barrel. It still leaks. It is hard to see exactly where it is coming from. top of slot or bottom because by the time i run to the front of the tractor after operating the valve everything is covered in oil.

 

[kennyd]

Original thread is posted HERE

Still no more idea's for you...unless the gland is cracked and you just can't see it. Do you have any local hydraulic shop's around? They could pressurize and test it under better conditions than you possibly...

 

[Treemonkey1000]

I'm with KennyD and think it may be cracked from being torqued sideways possibly. Can a machine shop Magnuflux that type of thing?

 

[Wayne County Hose]

The gland looks kinda far from the barrel to me. An oversize o-ring will only make things worse. Your problem is one of those that can't be fixed with pictures over the internet. Hopefully, you have a dependable, reasonable cylinder shop locally. My suspicions and experience would tell me to remove the gland, clean it real, real good, and inspect it very very closely for any cracks. Maybe even the end of the barrel too.

Andy

 

[Brad_Blazer]

While it's on the bench you could try pressurizing with air and doing a soap bubble test.

 

[M_Brown]

Thanks guys, The gap you see between the gland and barrel is normal on this cylinder. The gland can only go on in one location so that the retaining wire will feed into the slot in the barrel. Ya it does look a little weird. I took it to my local hydraulic shop and explained how it happened and what i did to try and fix it. He put it on the bench,the leak is coming from between the barrel and the gland. I will know more in a couple of days after he checks it out further. The prices from kubota on parts: The gland is $103.01 ,the barrel is $173.02, a new cylinder is $394.61. I did notice a small wear mark in the barrel where the o-ring for the gland sits maybe it is part of the problem. I'll post back when i find out more. Thanks again for your help.

 

[M_Brown]

Got my cylinder back from the shop the other day. I limited him to 1 hr shop rate and he spent about a 1/2 hr on it. Replaced the o-ring on the gland and it was still leaking, he change it twice with the same result as me. He was going to go further when i decided to try some parts swap with my good cylinder on the other side of the bucket. I got some o-rings and key stock from him and paid him for about 1/2 hr labor. He was not going to charge me anything but i told him he should get something for his time because he verified to me that i was not just messing up o-rings when putting it together. I took the gland /rod assy from the leaking side and put the piston from the non leaking side on it and put it in the non leaking barrel. It leaked like crazy. So then i put the non leaking gland and the piston from the leaking side into the barrel from the leaking side. It did not leak at all. So the Gland is bad. I inspected it more closely and found what looks like a crack inside where the rod slides through.I could not feel a crack until i took a very fine wire and pushed it up against the line that looked like a crack and it caught on it and ran down the line. So I believe it is a crack. Cool! that is the least expensive part at $103.00. So I will be ordering one of those on Monday.

 

[Wayne County Hose]

The gland looks kinda far from the barrel to me. An oversize o-ring will only make things worse. Your problem is one of those that can't be fixed with pictures over the internet. Hopefully, you have a dependable, reasonable cylinder shop locally. My suspicions and experience would tell me to remove the gland, clean it real, real good, and inspect it very very closely for any cracks. Maybe even the end of the barrel too.

Andy

Sorry, I probably should have told you to hold it up to a light or shine a bright flashlight in it. Most cracks or anything that would make it leak would show up. Glad you found it.