It's a depth issue. The brake pedal, after installing the new brake booster, didn't travel as high as it did previously. The stop light switch, as well as the gear shift interlock switch directly above it, had no way to adjust them so they would make contact. The are both mounted on a piece of steel suspended from the firewall. There is a bolt attaching it, but once I loosened it, I noticed spot welds on either side prohibiting it's movement fore or aft.

I finally just had to (with the switches removed from the bracket), brace my shoulder against the driver seat and push with a great deal of force to bend the bracket forward just enough so that it contacted with the rubber stop on the brake pedal lever. Once I reinstalled the switches they were properly contacted by the rubber stops on the brake pedal lever to respond normally.

I know I did a similar swap out on a Mazda truck years ago and was able to adjust the brake light switch--it had a lock nut and threaded shaft to allow its adjustment for proper operation.

 

This is so great. I've been trying to fix the brakes on 2001 F150 2 wheel drive for a year. Have replaced everything . Just finished the rotors and calipers' ,lines, master cylinder. Ill be trying this next. Thank You

 

Ok so I tried this and I still have a soft pedal. It fells like a leak in the system. When you press on the pedal it goes down slowly , but there are no leaks any where, I've checked it from front to rear and the master is not losing any fluid. At a lose here. Could my new master cylinder been defective?

 

Replaced my pads,calipers,rotors, drums, shoes and springs. Bleed the system 4 separate times to insure no air only to have a soft pedal that goes all the way down and doesn't stop safely. Looking at adjusting the brake booster on my 1998 5.4l 4x4 f150 with 68k miles . The bolts are so rusty from living in Michigan and buying this truck used as a project. Hope this works thanks for the pics of the tools and the booster/mastercyl very helpful for a visual learner.

 

Thank You for the tip, it worked just how you explained, the best tip I've ever received, brakes work just how I like them now.