Toyota Tacoma with Air Compressor for Towing?

I recently purchased a 1999 Toyota Tacoma SR5. I found out that it has a Firestone air compressor and air bags. I don't tow much so I am not sure what these are for. Can anyone help?

 

They are basically bags of rubber that go between the leaf spring and the bump stop on the frame. Look behind your rear wheels and you'll see them. They are used to help compensate for a heavy load, either in the bed or while towing.

If you aren't towing, they are still useful, you can change the pressure in them to correct for loads in the back of the truck, and compensate for sag in the springs (you shouldn't use them to "lift" the truck, just compensate and return to normal).

Don't let them go below 5psi or they will be damaged. Don't let them go over 100 psi or they will blow up. I run 10-20psi on mine if I'm not carrying a load, and have run as high as 40psi while towing. I just put some pressure in until the truck is back to it's normal running height. Makes a big difference!

If I were you, I'd leave them in. You may not use it much, but it is a handy addon, and they last a long time as long as you keep them above their minimum pressure.

-Sam