hey all, jus bought this 98 f150, noticed the brakes were airy and to use the brakes i gotta press all the way down, i changed the front brakes pads and rotors and added fluid but still nothing changed, i checked in the back to see if there was at least brake fluid going to them and i noticed this was broken and the hose was just hanging does anyone know if this could be
the issue for the brakes or what might be the issue?

images below for reference

 

I believe that is your axle vent. It shouldn't affect your brakes, but it's lowering the point at which you could get water into your axle, contaminating the fluid.

Start by bleeding the brakes to see if it improves the soft pedal.

 

The piece on the axle is just a hose nipple. Put a new length of hose on it and zip tie it up under the bed somewhere.

 

Could be an issue with your booster or master cylinder...bleed the brakes as noted above and see if that fixes, if not you have other (bigger) issues.

 

If the fluid has not been changed in in quite some time, if ever, old fluid can cause problems as well.

 

Start with gravity bleeding all 4 wheels, pay close attention to any air bubbles coming out.
Clean out the mud from the vent tube.
Yes, it goes up to the frame and has a umbrella in the end to prevent water ingestion.
The bleed should fix your issue.
Good luck
007