1987 K2500 Transmission Troubles..... HELP?

Basically the tranny cooler lines rotted out and leaked out all the fluid. Reverse was lost and after a quick refill came back. After the lines were replaced, there is no reverse at all. It backed out of the shop with some trouble, and as soon as it hit the resistance of the snow outside, reverse was gone. The transmission is a Th700R4. Is all hope lost, or am I missing something here? Any help would be appreciated.

Thanks,

Jay

The 700R4 tranny is such a good unit... I'm suprised you have any problems with it. HAHA, j/k.

If it has been a while since the last tranny flush, you probably should have it rebuilt. My guess is the new tranny fluid disolved some dirt and took out a seal related to the reverse clutch.