BX2660 Three point lift piston / cylinder scarred

[GNNOVA]

Anyone seen this happen. I started having a problem with the mower deck dropping down with in 10-15 minutes so I pulled the lift piston and found a lot of scarring on the lower stide Anyone seen this and what might have caused it.

 

[mcfarmall]

Welcome to the forum!

 

[DustyRusty]

A little more information is needed. What is the year of manufacture (if you know) and what is the model number(s) of your tractor, loader, and backhoe, should you have one?

 

[North Idaho Wolfman]

The only way you get scarring on the three point lift cylinder and piston is dirty fluid.
I'm not sure the piston is scarred, I don't think they are smooth new.
And I'd have to see the cylinder bore cleaned and better lit to see if it's really scarred.

Might just need a new O-ring.

 

[fried1765]

The only way you get scarring on the three point lift cylinder and piston is dirty fluid.
I'm not sure the piston is scarred, I don't think they are smooth new.
And I'd have to see the cylinder bore cleaned and better lit to see if it's really scarred.

Might just need a new O-ring.

Agreed....
A new O-ring, and that white plastic(?) ring underneath it.
The O-ring is easy, the white plastic(?) ring, not so much.
I had to take my (Ford) piston to a nearby Case dealer to put that white plastic(?) ring on for me.

 

[Daferris]

The white ring is a Teflon seal. They are used in automatic transmissions a lot. You stretch it to install. Then use a tapered tool to resize it for the bore. ( You could use a piston ring compressor to resize it) I would suggest getting the o ring and seal from Kubota as they probably are not too much $$$. The scratchs on the piston are not ideal but probably are fine. The bore is the concern it has to be smooth or it will wear out the soft Teflon seal quickly. Also check the clearance for the piston it should be about .002-.003" smaller than the bore I would guess.

 

[GreensvilleJay]

curious...
Does it matter that the 'recessed hole', bored in the bottom isn't centered ?? ( second picture ).
The O-ring appears to show a small vertical nick or slit ,just above the 'center line'...

 

[GNNOVA]

The tractor is a BX2660 and was bought new by the previous owner in 2010. I did post a picture of the piston and the cylinder, are you guys not able to see these? The tractor had the 200hr service done by a dealer by the previous owner and gave me the paper work to prove it. I would have thought the filter for the trans would have been changed then. I got it when it had 220hr on it. It started having this issue probably around 350hr mark. I changed the filter and fluid last year at the 600hr mark and the tractor now has 640hr on it. The fluid looked fine when drained. I cut the filter apart and did not see any evidence of metal failure. The o-ring is worn flat in the area of the scarring. I pulled it and the teflon seal. The teflon seal was easy because it has a split in it. Could someone let me know if you can see the pictures I posted or not so I can try to correct the problem. I did already order the parts to fix it. I have the same thought that the problem was from contaminated fluid but with its history I wanted a second opinion to see if these tractors have a problem with this. I think I am going to pull the pump since everything is apart and inspect it also.

 

[GNNOVA]

curious...
Does it matter that the 'recessed hole', bored in the bottom isn't centered ?? ( second picture ).
The O-ring appears to show a small vertical nick or slit ,just above the 'center line'...

I don't know if the hole matters. But the picture of the piston was taken after I han moved the o-ring around. It's not in the picture but the O-ring had a visible worn flat area where the scarring on the piston was. I am sure that is where most of the leaking was from.

 

[Russell King]

The tractor is a BX2660 and was bought new by the previous owner in 2010. I did post a picture of the piston and the cylinder, are you guys not able to see these? The tractor had the 200hr service done by a dealer by the previous owner and gave me the paper work to prove it. I would have thought the filter for the trans would have been changed then. I got it when it had 220hr on it. It started having this issue probably around 350hr mark. I changed the filter and fluid last year at the 600hr mark and the tractor now has 640hr on it. The fluid looked fine when drained. I cut the filter apart and did not see any evidence of metal failure. The o-ring is worn flat in the area of the scarring. I pulled it and the teflon seal. The teflon seal was easy because it has a split in it. Could someone let me know if you can see the pictures I posted or not so I can try to correct the problem. I did already order the parts to fix it. I have the same thought that the problem was from contaminated fluid but with its history I wanted a second opinion to see if these tractors have a problem with this. I think I am going to pull the pump since everything is apart and inspect it also.

Yes there are two pictures but the one down into the cy bore is not easy to see the walls.

try to take two more photos of the bore please, both with better lighting down the cylinder.
one similar to the one above of the whole cylinder from above and the other one from more of an angle to the bore showing the worst damage

post both as large images, one above of the cylinder is thumbnail size

 

[GNNOVA]

The white ring is a Teflon seal. They are used in automatic transmissions a lot. You stretch it to install. Then use a tapered tool to resize it for the bore. ( You could use a piston ring compressor to resize it) I would suggest getting the o ring and seal from Kubota as they probably are not too much $$$. The scratchs on the piston are not ideal but probably are fine. The bore is the concern it has to be smooth or it will wear out the soft Teflon seal quickly. Also check the clearance for the piston it should be about .002-.003" smaller than the bore I would guess.

I did not measure the bore yet but there is definately scorring in the bore. I priced the housing that the bore is in and it is over a thousand dollars. Ouch

 

[GNNOVA]

Yes there are two pictures but the one down into the cy bore is not easy to see the walls.

try to take two more photos of the bore please, both with better lighting down the cylinder.
one similar to the one above of the whole cylinder from above and the other one from more of an angle to the bore showing the worst damage

post both as large images, one above of the cylinder is thumbnail size

Thanks for letting me know about the pictures. Sorry but with the way the housing is made I can not get a better picture of the scarring. From what I can see it is as bad as the piston just not as far around the bore as the piston is.

 

[GreensvilleJay]

re: It started having this issue probably around 350hr mark. I changed the filter and fluid last year at the 600hr mark a

hmm, did you run this for +-300 hrs WITHOUT changing the filter and fluid ?

 

[PoTreeBoy]

For future reference, your tractor also has a suction screen. Was it removed and cleaned? The filter may only clean the hydro charge, I'm not sure.

 

[fried1765]

The tractor is a BX2660 and was bought new by the previous owner in 2010. I did post a picture of the piston and the cylinder, are you guys not able to see these? The tractor had the 200hr service done by a dealer by the previous owner and gave me the paper work to prove it. I would have thought the filter for the trans would have been changed then. I got it when it had 220hr on it. It started having this issue probably around 350hr mark. I changed the filter and fluid last year at the 600hr mark and the tractor now has 640hr on it. The fluid looked fine when drained. I cut the filter apart and did not see any evidence of metal failure. The o-ring is worn flat in the area of the scarring. I pulled it and the teflon seal. The teflon seal was easy because it has a split in it. Could someone let me know if you can see the pictures I posted or not so I can try to correct the problem. I did already order the parts to fix it. I have the same thought that the problem was from contaminated fluid but with its history I wanted a second opinion to see if these tractors have a problem with this. I think I am going to pull the pump since everything is apart and inspect it also.

"The teflon seal was easy because it has a split in it"

From that comment, I read that you believe the teflon seal should (normally) have a split in it.
A new teflon seal, or a teflon seal in good condition will not have a "split in it".
I suspect that someone might have previously replaced that teflon seal, and "split" it to make it fit!
Any split in that seal is NOT acceptable!

SEE POST #6 for proper installation of teflon seal!

 

[GNNOVA]

re: It started having this issue probably around 350hr mark. I changed the filter and fluid last year at the 600hr mark a

hmm, did you run this for +-300 hrs WITHOUT changing the filter and fluid ?

Yes I did but the dealer changed it after 200hr and the problem started after only 150hr from the previous oil change. But yes I was bad and went to long when I did the oil change.

 

[GNNOVA]

"The teflon seal was easy because it has a split in it"

From that comment, I read that you believe the teflon seal should (normally) have a split in it.
A teflon seal in good condition WILL NOT have a "split in it"

It had a angled factory cut in it just like some of the automobile transmission teflon oil seals have in them.

 

[GNNOVA]

For future reference, your tractor also has a suction screen. Was it removed and cleaned? The filter may only clean the hydro charge, I'm not sure.

No it was not. Where is it located?

 

[fried1765]

It had a angled factory cut in it just like some of the automobile transmission teflon oil seals have in them.

I do NOT believe that an "angled factory cut" in that teflon seal was actually factory done!
I suspect that the "angled factory cut" may have been done by some backyard hack, because he could not stretch the seal to fit.
I had to take my piston and seal to a tractor dealer to have the seal stretched to fit.
I later learned how they did it!
There should be NO CUT in that teflon seal!

 

[PoTreeBoy]

No it was not. Where is it located?

Left side, under rear axle.

There's a free downloadable pdf Workshop Manual available at Kubotabooks.