Case 450

I'm finally able to get back to playing with my case 450. I'm still having issues with the torque converter not having pressure when I start it.(Not all the time) I have changed the filter and the suction hoses, but every so often, I have to crack open the pressure line at the charge pump and run the machine till pressure builds up. I priced out a new pump from a Case dealer and it was $1,200.00. My next thing will be to do some work on the left side track chain. Are used chains an option? This machine seems to be the start of a huge money pit. Any suggestions will be appreciated Thanks Terry M.