Control Valve Rebuild: (Below is the steps I used for the control valve on my loader, yours may be slightly different.)
Tools needed:
Assorted wrenches
Torque wrench
O-ring removal tools (see pic at end)
Grease (I used synthetic grease)
Thread locker
Parts cleaner spray
Tooth picks
Clean shop towels / rags
Parts needed:
Seal (o-ring) kit
Pressure relieve valve (new)
Small amount of hydraulic oil
NOTE: After contacting the control valve vendor I was able to obtain a copy of the assembly drawing for my valve. This proved to be very useful as it listed both the torque specifications and which assembly items needed thread locker.
Procedures:
Remove the control valve from the tractor and place on a clean surface.
Remove cotter pins and other hardware for the control handles and set aside.
Load Check Nut O-Ring Replacement:
Remove the load check nut, spring and poppet. Pay attention to the orientation of the poppet.
Remove the o-ring from the load check nut.
Clean all the parts.
Install the new o-ring.
Using new hydraulic oil apply a thin coat to the new o-ring. Avoid getting oil on the threads of the nut
Replace the poppet, spring and then the load check nut into the valve.
Torque to required spec. (in my case 15-20 ft-lbs)
Repeat for other side.
Curl/dump Spool Shaft O-ring Replacement:
On the opposite end from handles there are two end caps covering the spool shafts. On my valve the two end caps are different height due to one having a float feature.
Remove the shorter end cap for the spool shaft.
Carefully slide the shaft out of the body from the end cap side. This end of the shaft also has a spring mounted to the shaft.
Clean the spring and end of shaft.
Apply new grease to outside of spring and end of shaft, set aside.
Reach into valve body to the o-ring groove with an o-ring tool to remove the o-ring. USE CAUTION TO NOT SCRATCH THE SURFACES OF THE O-RING GROOVE AND AROUND THE AREA.
Install a new o-ring in the groove.
Using new hydraulic oil apply a thin coat to the new o-ring.
Turn the valve body around, remove the old o-ring on this side and replace with a new one. Use the same caution as before.
Apply a thin coat of hydraulic oil to the new o-ring.
If the spool shaft is dry apply a thin coat of hydraulic oil to the shaft portion (not on the spring).
Insert the shaft back into the valve body slowly using a twisting motion. The twisting will help get the different features of the shaft past the new o-rings.
Install the end cap and mounting screws, torque to spec.
Raise/lower Spool Shaft O-ring Replacement:
If you’re raise/lower lever has a float feature the end cap is different than the curl/dump lever shaft. Mine has the float feature meaning the cap is taller.
To remove the cap, unscrew the two Detent Plugs located on the sides of the tall end cap. Under each detent plug is a spring and a ball. BE CAREFUL NOT TO LOSE THE BALL.
Once the springs and balls are out remove the screws retaining the cap to the body and take the cap off.
Clean all the parts with cleaner.
Carefully slide the spool shaft out of the body from the end cap side. This end of the shaft also has a spring mounted to the shaft.
Clean the spring and end of shaft.
Apply new grease to outside of spring and end of shaft including detent feature, set aside.
Reach into valve body to the o-ring groove with an o-ring tool to remove the o-ring. USE CAUTION TO NOT SCRATCH THE SURFACES OF THE O-RING GROOVE AND AROUND THE AREA.
Install a new o-ring in the groove.
Using new hydraulic oil apply a thin coat to the new o-ring.
Turn the valve body around, remove the old o-ring on this side and replace with a new one. Use the same caution as before.
Apply a thin coat of hydraulic oil to the new o-ring.
If the spool shaft is dry apply a thin coat of hydraulic oil to the shaft portion (not on the spring).
Insert the shaft into the valve body slowly using a twisting motion. The twisting will help get the different features of the shaft past the new o-rings.
Slide the cap into place and insert the mounting screws leaving them a little loose.
Using a toothpick insert some grease deep into one of the holes for the detent ball and spring. USE CAUTION NOT TO GET GREASE ON THE THREADS.
Insert the detent ball and spring into the opening
Install the detent plug using thread locker and torque to spec.
Repeat the procedures for the other detent ball, spring and detent plug on the other side of the cap.
Once the detent parts are installed, tighten the cap mounting screws and torque to spec.
This completes the o-ring replacement portion
Rich W.
Tools needed:
Assorted wrenches
Torque wrench
O-ring removal tools (see pic at end)
Grease (I used synthetic grease)
Thread locker
Parts cleaner spray
Tooth picks
Clean shop towels / rags
Parts needed:
Seal (o-ring) kit
Pressure relieve valve (new)
Small amount of hydraulic oil
NOTE: After contacting the control valve vendor I was able to obtain a copy of the assembly drawing for my valve. This proved to be very useful as it listed both the torque specifications and which assembly items needed thread locker.
Procedures:
Remove the control valve from the tractor and place on a clean surface.
Remove cotter pins and other hardware for the control handles and set aside.
Load Check Nut O-Ring Replacement:
Remove the load check nut, spring and poppet. Pay attention to the orientation of the poppet.
Remove the o-ring from the load check nut.
Clean all the parts.
Install the new o-ring.
Using new hydraulic oil apply a thin coat to the new o-ring. Avoid getting oil on the threads of the nut
Replace the poppet, spring and then the load check nut into the valve.
Torque to required spec. (in my case 15-20 ft-lbs)
Repeat for other side.
Curl/dump Spool Shaft O-ring Replacement:
On the opposite end from handles there are two end caps covering the spool shafts. On my valve the two end caps are different height due to one having a float feature.
Remove the shorter end cap for the spool shaft.
Carefully slide the shaft out of the body from the end cap side. This end of the shaft also has a spring mounted to the shaft.
Clean the spring and end of shaft.
Apply new grease to outside of spring and end of shaft, set aside.
Reach into valve body to the o-ring groove with an o-ring tool to remove the o-ring. USE CAUTION TO NOT SCRATCH THE SURFACES OF THE O-RING GROOVE AND AROUND THE AREA.
Install a new o-ring in the groove.
Using new hydraulic oil apply a thin coat to the new o-ring.
Turn the valve body around, remove the old o-ring on this side and replace with a new one. Use the same caution as before.
Apply a thin coat of hydraulic oil to the new o-ring.
If the spool shaft is dry apply a thin coat of hydraulic oil to the shaft portion (not on the spring).
Insert the shaft back into the valve body slowly using a twisting motion. The twisting will help get the different features of the shaft past the new o-rings.
Install the end cap and mounting screws, torque to spec.
Raise/lower Spool Shaft O-ring Replacement:
If you’re raise/lower lever has a float feature the end cap is different than the curl/dump lever shaft. Mine has the float feature meaning the cap is taller.
To remove the cap, unscrew the two Detent Plugs located on the sides of the tall end cap. Under each detent plug is a spring and a ball. BE CAREFUL NOT TO LOSE THE BALL.
Once the springs and balls are out remove the screws retaining the cap to the body and take the cap off.
Clean all the parts with cleaner.
Carefully slide the spool shaft out of the body from the end cap side. This end of the shaft also has a spring mounted to the shaft.
Clean the spring and end of shaft.
Apply new grease to outside of spring and end of shaft including detent feature, set aside.
Reach into valve body to the o-ring groove with an o-ring tool to remove the o-ring. USE CAUTION TO NOT SCRATCH THE SURFACES OF THE O-RING GROOVE AND AROUND THE AREA.
Install a new o-ring in the groove.
Using new hydraulic oil apply a thin coat to the new o-ring.
Turn the valve body around, remove the old o-ring on this side and replace with a new one. Use the same caution as before.
Apply a thin coat of hydraulic oil to the new o-ring.
If the spool shaft is dry apply a thin coat of hydraulic oil to the shaft portion (not on the spring).
Insert the shaft into the valve body slowly using a twisting motion. The twisting will help get the different features of the shaft past the new o-rings.
Slide the cap into place and insert the mounting screws leaving them a little loose.
Using a toothpick insert some grease deep into one of the holes for the detent ball and spring. USE CAUTION NOT TO GET GREASE ON THE THREADS.
Insert the detent ball and spring into the opening
Install the detent plug using thread locker and torque to spec.
Repeat the procedures for the other detent ball, spring and detent plug on the other side of the cap.
Once the detent parts are installed, tighten the cap mounting screws and torque to spec.
This completes the o-ring replacement portion
Rich W.
