I have a new to me 1989 Cat 426 Backhoe that just started having hydraulic issues with the rear boom. Today while digging stumps, one of the outriggers was put down and the lever got stuck in the down position and the outrigger extended to its full length and would not retract. The lever was frozen in the down position and would not budge no matter how hard I pulled on the lever. I was able to pull the floor pan out and tap the valve back down to the neutral position with a small hammer. After I got the outrigger valve unstuck, the outrigger would raise and lower but the rear boom and backhoe bucket would not raise or curl in. Actually the only functions on the back of the machine that will work are the outriggers and side to side swing. When I pull or push the boom up or down, boom curl, or bucket curl levers, nothing happens at all. No pump noise or nothing. The front loader bucket works as it should so what ever the problem is, it is confined to the rear of the machine. Any suggestions on what is causing this problem and a possible fix? Thanks in advance for any help.
After some online searches today, I tried raising the backhoe boom while curling the front bucket and that had no effect on the operation of the backhoe whatsoever. I guess this eliminates the resolvers causing the trouble. I did notice the outrigger valves are still sticking almost as if hydraulic pressure is putting them in a bind. A couple times I had to wait for the outrigger to fully retract before I could knock it into the neutral position. I can not figure out why only three functions out of the 6 valves on the backhoe will work. The working ones are the two outriggers and the boom swing. All others have no movement at all. Again, this trouble happened all at once. One minute everything was operating fine and the next minute I had all these issues. Please Help!!