Brake problems

It could be a few things. Collapsed brake hoses. Bad calipers that lock when hot. You need to find out what wheel is causing the issue.
 
Is this something that just started happening or did it start after something was replaced?

Sickfox is right. You need to figure out which wheel is the culprit. Mabey take a jack on your next drive so you can test once things lock up.