The stick on my '86 CAT 416 5PC01199 backhoe won't respond. Even with the hoses off on both ends of the cylinder, moving the stick control up and down will not send any new oil to either hose. From the outside, the stick valve seems to be going up and down normally without resistance. With the hoses disconnected still, and curling the bucket, oil did shoot out the stick cylinder hoses. I marked up the pictures below to try to convey this easier.
Blue is the stick valve body.
Red is the adjacent bucket curly valve body.
Yellow are the seals and BB I replaced in the stick valve.
From searching through older threads, I've found enough to suggest when one function on the hoe isn't working, or is slower than expected, first thing to check are these seat and resolver valve seals. Seals on both that seating BB bolt and the underneath resolver were old and cracked. All swapped for new. Still no oil getting to Stick Cylinder. I've read enough to suggest it could still be the seals on an adjacent valve (the bucket curl did send oil to stick cylinder), but possibly any one of them?
I still don't really grasp fundamentally what's going on with this seating valve and resolver valve and how it functions, or is supposed to.
Asking for a beginners explanation on how the internals of this valve body work, and any recommendations on where to go next. Wondering if I should start by replacing all other seat and resolver seals, or pull the control lever valve out of the stick housing and look for blockages or something like that.
Appreciate any education and recommendations on what to try next!
Thank you.
-Sean
Blue is the stick valve body.
Red is the adjacent bucket curly valve body.
Yellow are the seals and BB I replaced in the stick valve.
From searching through older threads, I've found enough to suggest when one function on the hoe isn't working, or is slower than expected, first thing to check are these seat and resolver valve seals. Seals on both that seating BB bolt and the underneath resolver were old and cracked. All swapped for new. Still no oil getting to Stick Cylinder. I've read enough to suggest it could still be the seals on an adjacent valve (the bucket curl did send oil to stick cylinder), but possibly any one of them?
I still don't really grasp fundamentally what's going on with this seating valve and resolver valve and how it functions, or is supposed to.
Asking for a beginners explanation on how the internals of this valve body work, and any recommendations on where to go next. Wondering if I should start by replacing all other seat and resolver seals, or pull the control lever valve out of the stick housing and look for blockages or something like that.
Appreciate any education and recommendations on what to try next!
Thank you.
-Sean
