A leaking hydraulic cylinder on one of the stabilizer arms on a backhoe can quickly become a hazardous situation. If a stabilizer arm fails while you are working, the backhoe could become unstable and tip over. This could damage the backhoe and cause serious injuries to you the operator if the backhoe lands on top of you. If you are new to backhoe maintenance and repair procedures and want to try to fix the problem yourself, here is an overview of what you have to do to repair a leaking hydraulic stabilizer arm on a John Deere 510 backhoe.

Remove Cylinder Shaft

The first thing you have to do is disconnect the hydraulic hoses going to the cylinder. There will be hydraulic fluid in the hoses, so make sure you have a five-gallon plastic pail that you can put the hoses into as the fluid drains out of them.

You will need to remove the set pin for the shaft on the cylinder housing. The set pin keeps the shaft from spinning, moving and falling out of the cylinder housing. The set pin is located on the cylinder housing just above where the shaft enters into the cylinder. You can remove the set pin with an Allen wrench.

There is a large cap on the end of the cylinder housing right where the shaft enters into it. You'll need a large pipe wrench to unscrew the cap.

The shaft is connected to the stabilizer with a thick pin. Remove the pin by pounding it out with a hammer and a large flathead screwdriver. You can now pull the shaft out of the cylinder housing and take it to a clean work area where you can keep all the parts organized as you take the piston, O-rings, and seals apart.

Replace O-Rings and Seals

The best thing to do is buy an O-ring and seals kit either from a parts store or online for the piston and shaft. The kits will come complete with all the parts you'll need to fix the leak.

You need to remove the big nut on the end of the shaft end that goes into the cylinder housing. Once the nut is removed, you can unscrew and remove the piston head on the shaft. Keep all the parts together in the order in which you took them off of the shaft. You might only have only one or two worn seals and/or O-rings on the shaft, but since you have everything taken apart, you might as well replace all the seals and O-rings with the new ones that came in the package. The package will come with a set of directions that show where each seal and O-ring goes.

Put Everything Back Together

Place the piston parts back onto the shaft and replace the big nut that holds everything together. Slide the shaft back into the cylinder housing and screw the cap back on with the big pipe wrench. Replace the set screw and reconnect the end of the shaft to the stabilizer. Reconnect the hydraulic hoses and fill up the hydraulic reservoir with fluid. Turn the machine on and open the bleeder valve(s) on the cylinder to release trapped air inside the hoses. Move the stabilizer arm until hydraulic fluid comes out of the bleeder valve and then close the valve. The backhoe is now ready to go back into service so you can get your job done.

For more information, contact a hydraulics repair company in your area.