It's very likely that your axles are Dexter and have self adjusting brakes. This is the link to Trekwood showing the axle and brakes for the 6,000 axles, and they show self adjusting. https://www.trekwood.com/products/50...-E-Self-Adjust
You can also crawl under your rig and look for a label pasted on the rear of the axle tube that will have manufacturer info, and if it indeed is Dexter, you can call them to confirm what it was equipped with when delivered to Keystone. This is the label from our axles, 7,000 lb axles, along with the number stamped in the axle tube.