Bobcat 773 -- 500,000 model

[Fishfiles]

This post is for a good friend who is far away , I am trying to help him long distance , he is a very good Bobcat mechanic as he worked at the dealer for quite a few years and has had help from the dealer service dept several times on this problem , a grapple hose blew and two new hoses were put on the machine , 5 minutes later the grapple stood stuck on , after disconnecting the aux stem coils , cleaning and swopping the stems , and disconnecting the hand controll it still is engaged , blocking off the power Bobtack , they tried ll kinds of stuff Bobcat suggested a new controll valve as it must have a crack , changed the valve and problem still exist , I am telling him I think that a piece of rubber or wire from when the hose was cut which may have got into the system , probally the stem vavle , and stuck it or something else , he says the stem can be entergized off the machine and works fine , sees them move and click , swopped the postions and same results ------- langnappe info ------ whe you pull the aux trigger while the hydraulics are stuck engaged it stops the flow , but when you do this the stems are disconnected electrically at that time , so the electric signal from the trigger does go to some other function that has an effect on the machine but may not have anything to do with the problem , anyone seen this happen

 

[perry]

Reads like he tried everything?, please keep us posted on results. Tazza might have a opinion?.

 

[Tazza]

Reads like he tried everything?, please keep us posted on results. Tazza might have a opinion?.

I'm only new to the late model machines so i may have a few things wrong here.
So, the flow only gets stuck on electrically? as in if you remove the wires to the coils everything is fine? If you get it in the fault condition can you lift the cab and remove the wire to the coil and does it go back to neutral?
I was thinking possibly the controller was a problem by doing silly things but if removing power doesn't change things it would have to be mechanical.
I have never pulled a stem out of an aux valve section but i did remove the lift lock stem today. If its the same, it has a small mesh filter that should stop any rubbish getting stuck, but after you said it happened AFTER a hose replacement it really does sound like you are on to something with thinking a piece of wire from the hose may be stuck.
If you can confirm its not electrical could it be a stem problem? when they were swapped, did the sticking change direction?