Hey Roger,
Tuneing Slide; Soak horn, ( In extremely Hot Water) ( minus valves, or any felt, or permerateing items or compoments that may hold water)...You need heat here to release the slide!!!
1. take a belt, wrap it around the tuneing slide, Then while grasping the valve caseing with great force, Snap the belt , if no luck, try again. Wiggle the slide a little back and forth ( or left to right) It should loosen up! Snap that belt again. ( it has to be an extreme snapping motion, not a "pulling motion") If or when it releases, lube it up, and stick each tube in and out indepentally while twisting to release the slide grease., Then reassemble the slide. Dont wreck horn, if no luck after 4 or 5 tries, go to a repair shop!!!
Sticky Valve;
2. Remove all valves, slides, Power spray all ports all slides, "snake" ( 1st, 2nd, 3rd valve ports) in shower, If you have'nt already " snaked" the horn Be careful not to muscle the snake thru the holes in the valves, ( damage could occur).
Now, getting to the sticky valve in question, Take the valve in question, and rub down with vertical motions with a " Miracle Cloth" ( purchase this at your local music store, or if not anticque, or hardware store) Google it if you have too, just get one!!!
Vigourouslly rub up and down, this will strip some metal off the valve, ( or other matters the valve sticks up on). Not too much though!!! Totally rinse off the valve, and air dry, blow dry ( whatever) Just dont dry with a cloth, Oil the valve up, and off you go ( hopefully)!!!!
If above methods didnt work for you, please consult your local repairman,...... and dont mention my name!!!!
love you guys!!!....... Hooter