Front brakes seized up, any ideas??
 

Hello so today I was driving down the road in my 86 300zx when suddenly my front brakes locked up, my front right tire was completely locked up and I think my front left was also locking up but I can’t be for sure on that. Anyways I left my car there and left for tools and when I got back around 30 minutes later the wheels were unseized and I quickly drove home. Does anyone have any thoughts as to why this would happen? Help would be greatly appreciated, thank you