I should have looked at this thread when it was first posted. I too have a Great Bend loader. There is no documentation anywhere today, unless you find a used manual on Ebay. They were in Great Bend, Kansas (?), later got sold to Bushhog who immediately not only shut them down but also destroyed all support documentation, according to a friend who works for a competitor. I inquired, Bushhog would only sell me a manual for their current products, nothing specific to my loader is available from them.
Ok, that said, 1) ignore the appearance of your hoses. They are double layer and even the rubber missing off the outer layer doesn't mean it is about to fail. I have hoses that have looked like that since I bought the tractor in 2003. Watch for swelling, that is the sign of imminent failure, replace that one hose.
2) Great Bend used 100% generic stuff. Any hydraulic shop anywhere can make up a replica hose in 20 minutes for you. Expect around $25 each.
Over 15 years I've only replaced a few hoses that failed. I've torn off several more rasseling downed trees that for example rolled over unexpectedly. And I replaced the loader control, because after 30 years it dribbled on my foot when heavily loaded.
Photos, 2007, before the old control started dribbling. I've only replaced three of these hoses 11 years later.
And four of the six hoses that reach the (new) loader control are still original from 1980.
Actually I've had more trouble with backhoe hoses, I suppose because they operate often at maximum pressure unlike the loader hoses.
