How to Rebuild or Repair Case 580 Tractor Backhoe Hydraulic Cylinders
Backhoe Hydraulic Cylinder Rebuilding
A tractor backhoe or front end loader is one of the handiest pieces of equipment used on the farm or on a construction site. These fine machines use a variety of hydraulic cylinders for lifting, digging, moving earth, digging ditches, and many other construction uses.
Occasionally these hydraulic cylinders need to be rebuilt because of leaking seals around the piston rod. Having a repair shop do this for you can run into quite a bit of money and also cause a long wait while the hydraulic cylinders are being rebuilt for you.
This article is intended to help you rebuild and repair the backhoe hydraulic cylinders on your particular machine. Even if you are not experienced in this type of hydraulic repair, this article will guide you through the steps needed to rebuild the backhoe hydraulic cylinders yourself.
Hydraulic Cylinder Rebuild KitsClick thumbnail to view full-size
How To Obtain The Correct Hydraulic Cylinder Rebuild Kit
Finding the correct hydraulic cylinder building kit is the first step in the rebuilding process. Some backhoes and front end loaders may use several different makes of hydraulic cylinders to perform the same function on your particular machine.
The Case 580C backhoe being repaired in this article is a prime example of such an instance and is therefore a perfect example for explaining the hydraulic cylinder rebuild process.
The Case 580C backhoe stabilizing jack being repaired listed two different rebuild kits for the hydraulic cylinder used to work the jacks. One has a one piece piston while the other used a two piece piston. It is very important to get the right hydraulic cylinder rebuild kit before starting the repair job. Once you disassemble the hydraulic cylinder you do not want to wait for the correct kit to arrive.
The correct part number is usually stamped into the gland of the hydraulic cylinder. Getting the correct rebuild kit should pose no problem if this part number can be found intact and readable. Even if you can only read some of the numbers the right rebuild kit can usually be found. You may find this kit online or through a tractor dealership.
Making The Gland Removal ToolClick thumbnail to view full-size
Gland Removal Tools
Safety is an important factor in rebuilding hydraulic cylinders, so be careful and do not hurry the job. Always take time to study the parts you remove if you don't have a schematic of the parts.
Take a photo if possible before each step to avoid confusion during the reassembly process.
After removing the yoke from the stabilizing jack stand by pulling the retaining pins, drop the jack to the ground and place a board or some other non metal object beneath the cylinder to keep it steady and to prevent dirt from getting on the parts.
It is important to not scratch the piston rod or other parts of the assembly. A marred piston rod will cause the new seals to wear quickly.
The gland on this particular hydraulic cylinder uses a common four hole system for removing and replacing the gland in the cylinder itself.
You may purchase a tool made just for this job, and there are a couple on this page, but since I have the tools and metal I prefer to make my own.
Each hydraulic cylinder, or tandem cylinders may use a different size gland removal tool which runs into quite a bit of money if you buy them.
By making your own you will eventually have a complete set. I make my gland removal tools from old plow points, case hardened bolts which fit the holes, and a piece of sturdy pipe.
An acetylene torch and arc welder is used to shape the tool and weld in the prongs made from the bolts.
Before attempting to remove the gland, loosen the hydraulic lines to allow fluid pressure to release and prevent a vacuum, making removal of the piston more difficult.
Removing piston and gland from piston rodClick thumbnail to view full-size
Disassembly of Piston And Gland
After completion of the gland removal tool, it is a simple matter of unscrewing the gland from the cylinder and removing the piston rod from the cylinder itself. Extending the hydraulic cylinder to its full length before removing the gland will save you the trouble of having to pull the piston rod very far to remove it. Use a sturdy point to attach the piston rod yoke to in order to unscrew the retaining bolt from the piston rod.
I normally use the original yoke connection if possible. Since a thread locking substance is used to keep the retaining bolt from vibrating loose (a very dangerous occurrence) it may be necessary to heat the end of the retaining bolt before you can get it to break free from the threads. Keep the torch flame away from the piston itself and concentrate it on the center of the bolt.
With the retaining bolt removed the piston and gland should separate from the piston rod easily. Place these pieces on a clean surface at a comfortable working height and check the seals from the hydraulic cylinder rebuild kit to ensure they are the correct size. It may be helpful to take digital photos as you go to ensure the correct replacement of the new seals.
Gland Removal tools
For easy removal of Hydraulic cylinder Glands.
Removing and Installing the SealsClick thumbnail to view full-size
Installing The New Rebuild Kit
After removing the old seals be sure to clean the piston and gland as best you can before installing the new seals. Any grit or sand may damage the new seals. Be careful not to break the rubber or cellulose seals during reassembly. The old piston seal which installs in the gland end ny be inserted by using the old seal to drive it in. In this hydraulic cylinder the retaining bolt washer was the correct size for the purpose and worked well.
Do not be troubled if there are extra seals which appear to have no place in either the piston or gland. The same kit may be used for several models of hydraulic cylinder and extra parts are often included. Once this part of the process is completed you may reassemble the piston and gland on the piston rod in preparation for the retaining bolt. Clean the threads in the cylinder and lightly grease the piston and gland seals.
Clean the retaining bolt threads and the threads inside of the piston rod and then apply a thread locking substance to the threads. Torque the retaining bolt very tightly and insert the piston rod assembly into the cylinder. It may be necessary to tap the gland against the threads in order for the tool to begin engaging the threads. Tighten securely using a lever to ensure the gland is securely attached.
Completing The Hydraulic Cylinder Rebuild
Insert the pins in the jack stand and retighten the hydraulic lines. Be sure to attach all retaining clips securely. Operate the cylinder until the air is removed and the hydraulic cylinder is working smoothly. Check for leaks and the job is done. This same technique is used for almost all types of hydraulic cylinders.
I hope my article helps you with your hydraulic cylinder rebuilding process. Please feel free to ask any questions you may have in the comment section at the bottom of the page. Good luck on your repairs and thanks for reading my article.
Finishing and testingClick thumbnail to view full-size
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.