Im am currently replacing leaf spring on my 1990 ford ranger.I got used springs from a junkyard to replace them. The bolts on the springs that hold on the brackets wont come out. How am i supposed to get the bolts to come out. I soaked them in rust buster twice, and tryed to use a air hammer to vibrate them out, but they still wont come out. Any suggesstions would be nice.

 

Heating them up (very hot) with a torch, and then putting the air hammer-gun to them should do the trick.
Try to aim the heat as near as you can on the bolts/nutsat thescrew into points.

 

Heating them up could seize them worse - plus you'll need a mask for the burning rubber and maybe a jug of water or an extinguisher just in case.. If you heat around on the actual leafIT instead will expand releasing the pressure (to help the bolt stay shrunk instead of expanding also hold an ice cube on just the bolt end(s). If all else fails - you could stand to use a blowtorch if you keep some water handy to put out the rubber fire and you watch to be sure you're far enough from the gas tank and spout with the flame and hot shrapnel. If no clearance for a torch and/or no experience with one manual is the best way - hammer it back and forth like a madman. Maybe you could spin it slow with the air gun while you spray penetrant on to help soak it in - just be sure the penetrant isn't badly flammable and keep the speed down on the gun a bit. If all else fails remember before starting - the bolt will never come out without going through hell if you don't relieve the hanging pressure by setting a jack underthe springand barely (lightly) raising the spring to hold it and release the pressure of it hanging on the bolt.

 

Bottom-line: there are two options as it relates to frozen bolts & nuts....either cut them with a chisel (Air-Powered or Manually), or you put heat to them. In your case, I would suggest using heat would be your best bet overall. You mustget the metal very hot, and then quickly attempt the unscrewing as soon as you take the flame away from themetal. I've done this procedure over the past 30 years time after time.

 

You could also try a saz-all with a metal blade

 

Are you going to use new bolts? if soo just cut old ones off to make the job faster and easer

 

see if you can borrow or get a hold of a bigger impact gun, if a nice big impact can't get those bolts off, you might as well just cut it all out with a torch, your replacing it all anyways right, just be careful what you cut, and watch where your flame is