First off, thanks to everyone who has spent so much time answering my questions. In everything that I've involved myself with, my prior background has provided a bit of a foundation when learning about this new thing. The backhoe has been completely different. So much of what I have - tools, techniques, understanding and experience don't apply at all. The learning curve has been like a cliff face, and I appreciate everyone sharing their knowledge and experience to help me along. About a week ago, I parked the hoe in my driveway, and started doing maintenance. Replacing rusted bolts to things that need to be opened (battery box, floor plates, etc), changing fluids and filters, greasing fittings, etc. I locked the backhoe arm in place with the drive lock, and kept it about 6 inches off the ground. I did not lower it at the time. Front loader bucket is on the ground. After about a week, the back bucket has dropped six inches or so, and is nearly on the ground. Is this normal that the hydraulic cylinders are "leaking"? There is no loss of fluid outside of the cylinders. It's just that the arm is not staying up. Thanks
In the case of a backhoe, yes, a small amount of "drift" in hydraulic cylinders is normal. Note that drift can be caused by any relevant part of the system, not just the cylinder.
I would say that’s normal. Some drift will occur when the pressure in the cylinder or the circuit equalizes.
Thanks.
my 555e does the same thing. I also get drift with my bucket curl cylinder. When you reference “drive lock” I would assume you mean the boom pin. You are probably noticing the curl drift as I suggested and being that it’s only 6 inches of the ground, it’s not going to look much different.
I have seen it be worse if the fluid level is low as well
Yes perfectly normal.
No such thing as a perfect seal, ever. Every hydraulic machine will leak internally and drift, most manufacturers publish acceptable rates in the service manuals.
It should be noted that cylinders drifting down over time is normal, them falling down while you are trying to work is not normal. If you have cylinders that are spewing oil when functioned, you need to rebuild the cylinders. When I unlock my boom and have it extended out, pointing to the sky, you can look real close and see it slowly dropping. I can still operate it just fine, but it makes a mess all over the lower part of the hoe and needs new seals.