Altec Boom upper controls having issues

[atmelt]

I have a 1987 gmc topkick with altec boom, the lower controls work perfect but the upper controls work besides the upper boom will not go down unless the lower controls are moved? When i try to lower the upper boom i can see the lower controls move but it is not going far enough to move the boom down and now the lower boom up is very slow with the upper controls but works perfect with lower controls? also when the lower boom goes down the hydraulic oil bubbles/foams up and come out the cap on the tank?

I do not know to much about bucket trucks im just trying to figure this out without having to take it to a shop.
Hopefully someone on here knows more about this situation.
God bless