My brakes were having an issue when I applied the pedal it would start to brake and then I would feel a pop sensation and the pedal would drop an inch or two and catch again. I replaced my load proportioning valve because I had an 86 with this problem before and that was the fix. I no longer have the pop but my issue is that if i push the brake pedal quickly while driving it brakes normal. If I push the pedal in slowly it travels nearly to the floor before I get any braking. Thanks for any input.

 

Thats a weird one...I wish I knew but Ive never heard of this before