Tractor Repair: Hydraulics, lift, up

Question
Allis Chamlers D15 series 2 gas. As soon as startes raises to maximun hight and will not go down

Answer
hi John i don't know this tractor but from what you are saying i recon there must be some part of the quadrant lever or its linkage after coming loose or off totally and the spool is stuck in the up position i would inspect the lever and if possible remove an inspection cover to inspect the internal linkage parts.in other words your moving the lever but the lever is not moving the spool.im taking it for granted that the lift drops when the tractor is switched off for a while if it doesn't drop over night you could have something mechanical blocking the lift
there is a site called (tractor repair manuals . Com) they have it for $47
and I've seen a cd version on ebay for a lot less but i prefer paper manuals a lot handyer you can have them with you as you work