I've never lubed mine as I don't like the idea of anything potentially getting on the rotor or pads. That being said, I'm not sure I would call these "sliding pin" brakes in the same sense. I thought sliding pin calipers were ones were the whole caliper floated and slid on pins. The Viper setup is a fixed caliper that just uses retaining pins to hold the pads in place. You could probably put a little **** on the pins or the ears of the pads where the holes are for the pins, but I've never seen a need to. You would be able to do that without removing the caliper though.
yes You are correct they are retaining clips. Yesterday I had a good look at the calliper and noticed the ears or where it sit on the pads where very crooked. I took it apart and lubricant the retaining clip sanded a groove that was cut in the retaining clip and clean. Problem solved Thanks