Dragging front brake

The 83 Nighthawk 650 has been making good progress, it was dripping gas out of #4 carb till I rapped on it with a screwdriver, which I learned here. My son dropped it on its right side on some grass this afternoon and the front brake locked up when it was righted. I cracked the bleeder which released it but it grabs and won't release almost immediately. What am I missing here? I see no damage to the caliper, hose or lever.

 

First thing , is it an original Honda lever or a jobber one?
Remove the lever , pin and brass slug that is in the lever that pushes the piston and see if that corrects the problem. Remove the cap on master cylinder and see if any debris is floating around that may be causing a blockage of fluid returning to reservoir.

 

Thanks for the quick response. I believe it is the original lever and will check the mechanism. I thoroughly cleaned the mc and flushed the brake fluid but I'll double check as well. I did lose a little fluid when I cracked the bleeder so it may need to be topped off. Thanks again.

 

One other possible is the brake line is deteriorating inside and blocking fluid.
May be time for new brake lines.

 

It's 33 years old. It's time for a good going through and new everything (rubber parts).

 

I will go through it and replace all old rubber. It seems like it might be a flap in the hose because pressure releases when I crack the bleeder but won't release when the lever is released. M/C looks clean, so it's either in the hoses or calipers, so they're coming off. I always see references for steel braid brake lines. Are they worth it for an older bike and where do you find them?

 

I see them on eBay. Is Galfer a decent brand?