m54 tank hydro noise

Hi, I just replaced the right hand wheel motor assy on my 2010 m54 tank.I know there was/is some air in the lines but after mowing for 10 mins it started making a loud squealing noise back there by the pump on the right side.I opened the relief valve while it was running for about 15 secs.I started mowing again and this time it did take longer to start making the noise again. Could it be just working the air out? It also doesn't want to turn to the right when it does this.

I have noticed that it seems like it wants to start the squealing noise after its ran for a little while. Could this be a needed adjustment or is my hydro failing now too?

I had a problem with my fathers mower just the same problem as yours. Believe it or not, the transmission went bad unfortunately.