Troubleshooting brakes

Jump to: navigation, search
(cleanup)
Line 1: Line 1:
'''Details on troubleshooting various brake problems'''.
+
'''Brake pedal goes to the floor''.
  
 
==Brake pedal goes to the floor==
 
==Brake pedal goes to the floor==
Line 6: Line 6:
 
#On a level floor or better still on a car lift, raise car, and if necessary, use axle stands that will safely support the weight of your car; obviously you dont need axle stands for car ramp/lift.
 
#On a level floor or better still on a car lift, raise car, and if necessary, use axle stands that will safely support the weight of your car; obviously you dont need axle stands for car ramp/lift.
 
#First make sure the brake master cylinder is filled with good quality fluid, preferably new and from a sealed container
 
#First make sure the brake master cylinder is filled with good quality fluid, preferably new and from a sealed container
 +
If it is empty check for leaks, if found repair leaks and continue, if not continue to next steps
 +
 
#Surround the master cylinder with some clean rags just in case of any accidental spillage of brake fluid.
 
#Surround the master cylinder with some clean rags just in case of any accidental spillage of brake fluid.
#On most cars, trucks, etc. you will find four flexible brake hoses one on each brake caliper or drum on the front, then one or two between rear axle and floor at the rear. If you have the correct brake pipe clamps use them to clamp the flexy pipes, or with great care vice grips could be used instead --  one word of caution here do not try this on aftermarket braided piping.
+
#On most cars, trucks, etc.  
#Now your helper, who is in the driver's seat, presses the brake pedal. If the pedal still goes to the floor, then bleed the master cylinder by opening the one or more brake pipes at least halfway out the threads. Get your helper to pump the brake pedal slowly; hopefully brake fluid will appear and be absorbed by the rags you positioned earlier, now tighten up the brake pipes on the master cylinder.
+
#Now your helper, who is in the driver's seat, presses the brake pedal. If the pedal still goes to the floor, it is time to attempt to bleed the master cylinder. You can use a master cylinder bench bleed kit which will install into the line ports and have an attached hose that goes back into the reservoir. Push and release the pedal until there are no air bubbles.  
#If you still have no firmness on the brake pedal then either replace the master cylinder with a known good one or a new one. Sometimes a rebuild kit for the Master cylinder is available, so you have options. Once again, bleed the new master cylinder before proceeding.
+
 
#The second possibility is your helper says the brake pedal is rock hard with no travel, you then remove one clamp and your helper presses the pedal again; if the pedal remains hard then proceed and remove the next clamp, remove the next clamp and so on. If removing any of the clamps results in too much brake pedal travel -- bingo you have discovered the fault area. If it were the back axle then remove the drums as per Chilton or Haynes manual and carry out reconditioning as per book. Quite often all that is needed is the dust removing with an aerosol brake cleaner, then manually adjusting the brakes. If your vehicle has a brake proportioning valve of any type then make sure you understand its function.
+
#If you still have no firmness on the brake pedal then it is time to bleed the rest of the system. Have your helper push the pedal half way to the floor and open the bleeder on the wheel furthest from the master, close bleeder, release pedal and repeat until there is just fluid comming out, no air. Go to the next furthest wheel and repeat until all wheels are done. It is important that the pedal not be released while the bleeder is open or you will suck air back into the system. Once you have completed this procedure you should have a good pedal.
 +
 
 +
 
  
 
[[Category:Brakes]]
 
[[Category:Brakes]]
 
[[Category:Undeveloped articles]]
 
[[Category:Undeveloped articles]]

Revision as of 15:35, 27 August 2010

Personal tools
Namespaces
Variants
Actions
Navigation
Categories
Toolbox