My latest $40 eBay gamble; a
locking hydraulic drifting brake. Going to see if I can use it as an emergency brake (for short periods). I say short periods because I don't really trust it to hold pressure for hours / days, I just need something to hold the truck if I want to get out for a few minutes (like stopping to close the shop / gate as I leave, etc).
I still need to figure out the fitting sizes and a good place to mount it. I'm also debating between hard lines and hoses, probably go with hoses.