Bobcat t190 problem PLEASE HELP!!!

Hey all! I have been scanning this site for years now and finally decided to register. Awesome site! Here is my issue that I hope you guys can help me out with! I have a 2005 t190 with 1500 hrs on it. I recently bought it not knowing the previous owner didn't do any of the maintance. As soon as I bought it I went to dealer and bought all the stuff to do a full maintance. While doing the work I found the case drain on the right side of machine lightly dirty with some silver metal In it. The left side was heavily filled with silver metal chunks an shavings. I changed them both drained the hydraulic fluid did the other maintance and used the machine for one job! During the job the left side started squealing pretty bad! I stopped using the machine and took my final drives off to take them to be rebuilt. Well the place I took them to took them apart to inspect them and found that the final drives themselves were not damaged my problem was the brakes. The we're hanging up and causing problems, the worse being the actual brake housing itself where the gear is was grooved pretty bad. The problem is that the availability on that housing since mine is the 5 port is hard to come by! Long story short my only option was to buy 2 new drives! ($6700 ouch!) my concern now is what was causing the brakes to hang up? I am being told all kinds of things such as I need a new charge pump to the brake seals in the drive were bad which was what caused it. I just don't want to install these new drives and damage the new ones! Any suggestions on what I can do to test the other components or what else to check before I run the machine. Thanks all imput will be helpful!