I bought a 92 4runner with no front parking brake, and I recently installed one. I bought it used, which was a mistake bur whatever, already here. I'm trying to make it work but it seems like the cable itself is too long. I can pull the handle all the way and the lever which controls the rear brakes under the cab barely moves at all, also there is some noticeable slack in the cable when it is not being pulled. Not sure what to do here.

 

Under the vehicle, about half way back you should see a bell crank where the front parking brake cable attaches, along with the two rear cables. Make your adjustments there.

 

I can adjust the rear cables there, but I can't seem to figure out how to adjust the front one

 

If you had previously tried adjusting the e. brake by rotating the star at each rear wheel you’ll need to go and undo that. Back them way off. Then go to the bell crank and adjust. Once you have the parking brake tension set properly you can go to the rear wheels and make the final adjustment