truoble shooting brake system 72 f-250

[agee619]

where can i find a tutorial or some info on how to diagnose my brake issues? I want to repair it my self but am not sure what is the problem...???? my brake pedal goes all the way down but i get no pressure at all. I replaced the gasket for the master cylinder because it seemed to be all warpt. do i have to bleed the master cylinder????????

[FORDification]

Man...talk about coincidence! I've been working for two weeks on putting together such a tutorial, transcribing an entire 52-page Technical Service Bulletin article on every aspect of troubleshooting the brakes and brake components on all Ford vehicles...cars and trucks (including medium- and heavy-duty trucks). I spent the entire afternoon today getting it 99% finished up, and I'll be finally be putting the finishing touches on it tonight, by adding three missing illustrations. But you can be the first one to check it out, sans the illustrations. I'll be posting something in the Site and Forum Announcements forum when I get it finished up later this evening.

TSB Article 964 - Brake System Diagnosis

BRAKE SYSTEM PROBLEM CONDITIONS - TABLE OF CONTENTS

PROBLEM CONDITION
NOISE CONDITIONS

• Disc or Drum Brakes — Cars or Trucks Page
  • A. Noise at Brake Pedal or Dash Area
    B. Noise at Wheels — Only When Brake Pedal Pressure Applied
    C. Noise at wheels — Brake Pedal Pressure Released

VIBRATION CONDITIONS

• Disc or Drum Brakes — Cars or Trucks
  • D. Vibration at Wheels — Brake Pedal Pressure Released
    E. Vibration at Wheel(s) — Brake Pedal Pressure Applied

PERFORMANCE CONDITIONS

• Disc or Drum Brakes - Cars or Trucks (Including Air Hydraulic Wedge-Type and Cam-Type Air Brakes)
  • F. Vehicle Pulls to One Side — Brakes Applied
    G. Vehicle Pulls to One Side When Driving — Brakes Released
    H. Brake Grab or Inadvertent Lock-Up — Brakes Applied
    I. Excessive Pedal Travel and/or Low Pedal
    J. Brakes Do Not Apply
    K. Excessive Pedal Effort Required To Fully Apply Brakes
    L. Pedal Feels Spongy (Brakes Fully Applied)
    M. When Fully Depressed, Brake Pedal Slowly Moves to Floor
    N. Insufficient Braking With Brakes Fully Applied
    O. Brake Drag (Slow or Incomplete Release) — Brakes Released
    
    Brake Booster - Disc or Drum Brakes - Cars or Trucks
    P. Rough Engine Idle or Stall — Brakes Released
    Q. Rough Engine Idle or Stall — Brakes Applied
    R. Brakes Do Not Release — Trucks Only
    S. Brake Pedal Kicks Back When Applied — Trucks Only

MISCELLANEOUS CONDITIONS -Cars or Trucks

• • T. Parking Brake Will Not Fully Return or Release — Cars Only
    U. Parking Brake Will Not Fully Return or Release — Trucks only
    V. Parking Brake Requires Excessive Pedal Effort to Lock — Cars Only
    W. Parking Brake Releases Inadvertently — Cars Only
    X. Parking Brake Pedal Has Excessive Travel (Won't Hold) — Cars Only
    Y. Parking Brake Will Not Hold (No Application) — Trucks Only
    Z. Dual Brake System Warning Lamp Does Not Light
    AA. Dual Brake System Warning Lamp Stays Lit

PERFORMANCE CONDITIONS

• Air Brake — Air Supply System — Trucks Only
  • AB. Excessive Oil or Water in the Brake System
    AC. Continuous or Intermittent Compressor Knocks
    AD. Air Pressure Below Normal
    AE. Air Pressure Rises Above Normal
    AF. Safety Valve Blows-Off
    AG. Quick Air Pressure Drop With Engine Stopped — Brakes Released; Brakes Applied
    AH. Brakes Release Too Slowly or Will Not Release
    AI. Low Pressure Indicator Valve Does Not Operate

ADDITIONAL INFORMATION - (Additional brake-related TSB articles)

Just an FYI: When reference is made in this article to "trucks", they're generally referring to the medium- and heavy-duty trucks, not our light-duty pickups. Also, for your troubleshooting purposes, disregard any reference to cam-type or wedge-type brakes, as those are only on medium/heavy trucks.

[fordman]

a master cylinder gasket? what is that? where is it located at? the lid gasket? or did you rebuild the master and put new seals in it?

basically you would want to fill the master with fluid. and then bleed the brakes at the wheel cylinder starting with the furthest one away from the master. (passenger rear) then drivers rear. passenger front drivers front. watching for leaks as you go. if you never get any pedal but are seeign fluid at the wheel cylinders your master is probably just bad. or aleak in the lines someplace.

[Chaseman]

I had a similar thing where it went all the way to the floor just barely braking when i first bought it. So I just adjusted up the drums and the pedal came up with them.