Delete GTM Server via REST API

I am trying to delete a GTM server, but cannot seem to get it right. I am using the below but it is returning a 400 error. I am printing the server name before I delete it so I can see that it is there and it is correct. Any help?

b.delete('%s/gtm/server/%s' % (b.b_base, server_name), data=json.dumps(servname))