I have a Gilcrest pusher RWA on a 1660 that I have never used until now. When I turn it on I get a loud chatter in the hyd lines going to the motors. Thought it was air in the lines so went through the procedure in the combine op man. to get air out & it still has the chatter. The line are jumping around pretty good and I don't want to tear anything up. Any ideas what might cause this? I thought maybe i would go through bleeding procedure again in the morning to see if it helps. When rear wheel are jacked up wheels move like they are supposed to.