To repair leaking from the hole in the rear end of the remote valve , The valve spool needs to be removed from the valve body. The valve itself does not need to be removed from the tractor if this is the only leak. The following procedure explains how to remove the valve spool with the valve body mounted on the tractor.
First remove the linkage or lever from the spool and clean the front of the valve and spool. Next unscrew the large pipe from the rear of the valve. The pipe is difficult to break loose from the valve body due to the congestion in this area. Try using a 1 1/2" socket (preferably 6 pt) with an extension and breaker bar on the large hex nut with the hole where the leak is coming from. Most likely the nut will break loose from the pipe without turning the pipe. If this happens tack weld the nut to the pipe. Then using the nut unscrew the pipe. Once the pipe is unscrewed pull the pipe and valve spool out the back of the valve.
Once the spool and pipe are removed ,grind off your tack weld and unscrew the nut from the pipe. Next with the front flat part of the control valve clamped in a vise with the rear pipe end of the spool raised slightly higher that the front of the spool, unscrew the slotted plug from the rear end. This plug is up against a spring and may be slightly spring loaded so take care when removing. With this plug removed , remove the spring, then using a small magnet draw out the ball cup and ball. next using the magnet withdraw 3 more (smaller) balls. Once you have the balls removed slide the large pipe rearward off of the spool and actuator. The detent sleeve will come off with the large pipe.
Now you are looking at the actuator ( hollow tube with 3 holes in the side of it). Unscrew (RH thread) the actuator from the end of the spool using a tight fitting punch in one of the holed or a curved jaw vise grip. (dress up any damage cause by the vise grip). Be careful not to chip the hole if using a punch. The actuator is usually quite tight and a good initial thrust will break it loose. Once broke loose carefully unscrew the actuator by holding it securely because the large coil spring between the actuator and spool will force them apart. Note the position of the spring cup and front washer.
With the actuator removed from the spool using a thin pick or stiff wire push the actuator detent piston out of the actuator. If you are working on a early,style low pressure valve(2000psi) it will have an actuator piston as in our "B" kit. This piston is simply pushed into the actuator with the oring end towards the spool (external threaded end). Push the piston in until you can see the rear end of the piston protruding into the ball area of the actuator about 1/8. At this point this actuator is ready for assembly.
If you have the later high pressure valve (2500psi) it will have the actuator detent piston as in our "A" Kit
Install the tiny backup washer into the male threaded end of the new actuator, next install the tiny oring against the backup washer. Then apply grease to the pin and install it through both the oring and backup washer. Next drive the cup retainer into the end of the actuator (open or cup side away from the oring and backup washer). keep the pin installed through the oring and backup washer ( pin will be flush with oring while driving retainer in). Drive retainer in until you can feel resistance when sliding the pin in and out. ( the retainer needs to push on the oring enough to increase pressure on the pin ). You will need a punch that fits the inside diameter of the actuator perfectly. It is critical that you can feel that you have more resistance when sliding the pin in and out than before the retainer is installed. When you are satisfied with the position of the retainer, slide the piston so that the end in the ball area protrudes about 1/8". At this point the actuator is ready for assembly onto the spool.
Blow with compressed air through the rear hole in the valve spool to make sure the tiny holes in the glands of the spool are open and clean. ( Note the spool is mated to the valve at the factory and should not be exchanged )
Replace and or install the new oring in the kit onto the male threaded end of the actuator. Next replace the oring on the rear end of the spool with the new one from the kit. Then slide the collar onto spool as it came off. Next install spring cup.spring and flat washer onto the actuator and while holding the spring compressed thread the actuator into the spool. Make sure the flat washer has the centering groove towards the spring ( some washers do not have the centering groove). When tightening the actuator to the valve spool make sure you don't have the flat washer pinched in between the actuator and the spool. You should be able to pull the washer over the actuator against the spring.
Next replace the oring in the front of the valve body. Now clean and oil the detent sleeve and slide it over the actuator so the large end is towards the rear and flush with the end of the actuator. Next slide the large pipe over the sleeve,spring and flat washer. Now make sure to have the front of the valve spool clamped in the vise as before with the actuator end up slightly. With some grease on your fingers squirt the 3 smaller detent balls into the rear end of the actuator. The balls will be pushed inside by the 1 large ball until the 3 small balls find there home in the 3 holes of the actuator. The balls need to eventually be pushed out through the actuator holes and into the groove of the detent sleeve. Install the large ball, cup and spring. Push on the spring and move the pile and detent sleeve in and out slightly until you feel the 3 balls fall into the groove of the sleeve. Then install the slotted plug, screwing it in about flush with the end of the actuator. Now you are ready to slide the valve spool and detent into the valve body, using grease to ease the assembly. Thread the pipe into the back of the valve. Install the large plug and then tighten the pipe and nut with a 1 1/2" socket . Do not use a impact wrench to tighten this or you will break the valve threads.
Hook up the front control linkage and operate the valve. Adjust the desired detent release pressure with the slotted plug in the end of the actuator. install the push in plug/cap.
Good Luck
Joe