Why is the dust collection feature not working?
The dust shroud acts as if it is clogged and the dust collector is not doing its job.
The DeWalt D26451 Random Orbit Sander is a 5-inch sander with a 3 Amp, 12,000 RPM motor. DeWalt discontinued this model, but replacement parts for the D26451 can still be found online.
I have the same exact sander and this could possibly be a simple fix and your going to need something that blows air my preferred method is an air compressor but air in a can works to. You going to want to take the dust bag off and there is a gap on the front of the sander where there are metal fins that's the area where gunk builds and all you have to do is blow compressed air into that area. The other problem could be is you covered the holes on the sanding pad with your sanding disks and that's where the sander picks up the dust. If all else fails send it to the dewalt repair center go to www.dewalt.com then go to parts and information tab now on the top right corner there is a spot that says local service center and type in your zip code.
Good luck and I hope this helps!
My dewalt dustless 5 hole random orbit sander gave this problem even when I used it for the first time! Home depot said that all these sanders have the same problem but Milwaukee ones are better at dust collection than the cloth bag ones, also the shroud at the bottom of the sandpaper disc has to be vacuumed clean and empty the bag often when it is about 20% full. I returtned my dewalt for a Milwaukee and boy was I amazed!