John Deere 310D cylinder issues. Hydraulic oil question?

[Bobcat Crazy]

Hi All,
I hope you are doing well today and having great day. I have a couple questions of you more experienced people than I. I have a JD 310D backhoe that we use around the family land, it is not used commercially anymore but was before I bought it. I seem to need the cylinders rebuilt more often than I think I should need to. With light use I would think these cylinders should last for years once they have been rebuilt.

My question is, am I using the wrong hydraulic oil? Should I be using a thicker oil now that the machine is older? The cylinder outer barrels (not sure of proper name) and rods are in good condition so this is not an issue that is caused by a rusty rod or one which spots of chrome have peeled off.

I am pretty sure I am using AW46 hydraulic oil. Is this oil too thin? The wrong type oil? If so, what should I be using in it?

All help & advice is greatly appreciated?
B-Crazy

 

[Tinkerer]

Are you resealing them yourself or taking them to a cylinder re-builder ?
I ask this because the quality of the seal kits is very important.
AW 46 should be Ok as long as it meets John Deere's J20 specs.

 

[Bobcat Crazy]

I have done some each way and can't tell much of a difference. Maybe I just don't use it enough to keep them lubricated could that be a possibility?

If the oil is not too thin that is the only other thing I can think of.

 

[Finca SDR]

I use generic iso 68 hydraulic oil in my 310d. I wouldn't think it's the oil. My first guess was damage to the chromed piston rods but you said that's not the case.

 

[Midnightmoon]

What cylinders are the issue and what's failing? Maybe someone turned the relief pressure up to high for that function? Are you getting a full rebuild or just the outer seal? The outer is just a dust seal inside is where the issue is

 

[Vetech63]

Are you replacing the rod guide inside the gland when the cylinders are rebuilt?

 

[Delmer]

we'd need the old seals that only lived a few years to have a better idea what is happening. Any possibility you have a suction leak and you're getting air into the cylinders, that will damage seals relatively quickly.

 

[Bobcat Crazy]

I use generic iso 68 hydraulic oil in my 310d. I wouldn't think it's the oil. My first guess was damage to the chromed piston rods but you said that's not the case.

Rods are in really good shape. I think I will try the iso 68 hydro oil. Maybe the 68 is thicker than the 46. I don't remember why I use the aw46. I assume it was because when I went to buy new oil they told me the AW46 was premium oil. And I figured if it had been using regular grade oil certainly premium oil would be better. Of course an equipment rookie like me didn't consider the weight of the oil. Those equipment rookies (like me ) should ask for you Guys advice before instead of later!

Thanks,
B-Crazy

 

[Bobcat Crazy]

What cylinders are the issue and what's failing? Maybe someone turned the relief pressure up to high for that function? Are you getting a full rebuild or just the outer seal? The outer is just a dust seal inside is where the issue is

Turned up pressure? I had not considered that.
Yes getting full rebuild not just outer dust seal.
What cylinders? Not sure right now, my brother keeps the machine most of the time over on him mini-farm. When he has a leaking cylinder on it he takes it off and brings it to me to have rebuilt. Sounds like a good setup for him! I know right!

Thanks!
B-Crazy

 

[Bobcat Crazy]

Are you replacing the rod guide inside the gland when the cylinders are rebuilt?

Yes replacing all seals and guides.
I guess it could be something about the way my brother uses it, but normally he is easier on our equipment than I am so I doubt that.

 

[Bobcat Crazy]

we'd need the old seals that only lived a few years to have a better idea what is happening. Any possibility you have a suction leak and you're getting air into the cylinders, that will damage seals relatively quickly.

I guess that could be a possibility but if they were getting air into them wouldn't that cause them to be jumpy when operating them?

Thanks,
B-Crazy

 

[Tinkerer]

What brand seals did you use when you did the rebuilds ?
How long do they last before leaking ?
Is the oil leaking around the rod or is it the piston seals causing the cylinder to drift ?
AW68 oil may cause a slow engine cranking speed when starting it in the winter.
Usually air in a cylinder will cause it to bounce.

 

[Delmer]

Brother operating unit has been a leading cause of unexplained failure in my experience. I would not go with a heavier oil either. Oil would be one of the last things I'd suspect. Small air bubbles can diesel in the cylinder, damaging seals.

 

[Bobcat Crazy]

What brand seals did you use when you did the rebuilds ?
How long do they last before leaking ?
Is the oil leaking around the rod or is it the piston seals causing the cylinder to drift ?
AW68 oil may cause a slow engine cranking speed when starting it in the winter.
Usually air in a cylinder will cause it to bounce.

What brand?
I have used different brands. All the way from the John Deere local dealer, one seal kit from them (for the largest cylinder on the backhoe arm) which was over $500 for the seal kit plus having the cylinder rebuilt at the shop. To seals from Foxprints2003 on ebay, these seals hold up really good on my skidsteer Bobcat S185.

How long do they last?
Without actually tracking them on the calendar I would say I am building 2 or 3 every year. I supposed that means they last a year or year and a half. But again this is with very little use as compared to what they are built for. We my go a month or even two without using it.

Is the oil leaking around the rod or is it the piston seals causing the cylinder to drift ?
I am not sure how to answer this. Where could it leak other than around the rod? How can I tell the difference between leaking around the rod and knowing the piston seals causing it to drift?

Haha! The more I answer you Guys questions it shows me how little I really know compared to you!

Thanks for taking the time!
B-Crazy

 

[Bobcat Crazy]

Brother operating unit has been a leading cause of unexplained failure in my experience. I would not go with a heavier oil either. Oil would be one of the last things I'd suspect. Small air bubbles can diesel in the cylinder, damaging seals.

Okay so I am beginning to think the heavier oil is not a good idea!

Thanks!

 

[Delmer]

You're rebuilding them because they're leaking around the rod seal. The piston seals can leak internally and the cylinder will drop under load, but not leak externally.

 

[Bobcat Crazy]

You're rebuilding them because they're leaking around the rod seal. The piston seals can leak internally and the cylinder will drop under load, but not leak externally.

Okay that helps me, they are leaking around the rod externally.