how hard is it to bleed brakes?

Discussion in 'Fox 5.0 Mustang Tech' started by Jaswir, May 13, 2006.

  1. i have never bleed my brakes or ever seen it done... i want to flush my system and put new brake fluid in... just wondering if someone could explain it to me... and can it be done by ur self? and really is it as hard as i think it is... im kinda scared to do it because i think im gonna loose my brakes because i have no idea on how to do it??
  2. If you buy speed bleeders you can do it by yourself. If not, you'll need a partner to open/close the valve. I would spend the $20 for 4 speed bleeders. I bled/flushed mine.
  3. its not that hard it just takes time Bleeding the Brakes


    Bleeding the brakes requires a properly sized box wrench for the bleeder and the clear plastic bleed hose provided with your system. Good quality, non-silicone fluid is also a must. Baer Brakes has tested a wide variety of fluids and strongly recommends Performance Friction’s Z-Rated fluid #90016 for street and occasional track use (with Motorcraft PM1 our backup suggestion for this same duty). These two have been proven to be more effective than fluids that are often many times more expensive. For racing, Baer recommends and uses only Castrol SRF. Baer stocks and sells both the Performance Friction Z-Rated and Castrol SRF.

    Always remember, good to excellent brakes or fluid do not function without

    adequate cooling. In fact, the more serious your brake system, the more attention that needs to be directed to proper ducting, as they will generate more heat due to

    increased capacity.


    Proper Bleeding Technique

    Enlist someone who will help you bleed the brakes. Make sure they also read

    these instructions carefully (so they understand the goal).

    1. For systems which are essentially dry front and rear, start by filling the

    master cylinder with proper fluid. Pour slowly so as not to aerate the fluid.

    2. Next, move to the first caliper, attach the clear plastic bleed hose to the

    bleeder and open it. Hold the hose upright so that you can monitor the escape

    of air bubbles. VERY SLOWLY stroke the brake pedal by hand or foot until

    fluid comes out. Now close the bleeder.


    A. Have your partner very slowly, with modest pressure (approximately 25-30

    lbs.f.), stroke the pedal ONE TIME until hydraulic resistance is

    encountered. Ask your partner to hold at this point with the same modest

    and even pressure and notify you that he is “holding.”

    B. Open the bleeder, letting the pedal go to the floor or until it stops, using

    the same modest level of pressure, then close the bleeder again. Notify your

    partner “the system is sealed.” He can then slowly release pedal pressure.

    4. Repeat the BLEEDING SEQUENCE (never stroke the pedal more than one

    time) until all signs of air are purged (no bubbles) from fluid. IMPORTANT


    the fluid level after every third bleeding sequence or sooner if reservoir

    volume is very small.

    5. Before moving to the next caliper, take a small block of wood or a plastic

    hammer and carefully tap the caliper to dislodge any additional air bubbles

    that may be trapped. Then bleed one last time.

    6. Move to the next caliper and repeat the procedures previously outlined.

    Continue until all calipers have been bleed.

    Before re-installing wheels and placing the car on the ground, we recommend you

    carefully wipe clean all caliper surfaces, hose joints and fittings, making sure

    they are all dry and free from seepage. If not, inspect and tighten appropriately. Spray all rotor surfaces with Brake Klean® or a similar product to remove all dirt and oils from your hands that may have been transferred to the rotor during assembly. Also remember to remove the nut that has been holding

    rotor in place before attempting to re-install the wheel.

    For street use, as with any time you open the brake system, it may be advisable

    to repeat the bleeding procedure after driving the vehicle for a day, as driving

    the car may dislodge some additional air bubbles. For competition cars, we

    recommend repeating this procedure directly after at least the first two

    sessions the car is on track and at the beginning of each race weekend


    Even if your pedal is high and firm and additional bleeding is deemed

    unnecessary, always inspect the calipers, hoses and fittings after the first

    outing for signs of any fluid seepage and correct immediately
  4. Garden Sprayer Pressure Bake Bleeder

    1 each pump type garden sprayer, 1 - 1 ½ gallon capacity (size doesn’t matter much, it just has to be cheap and small enough to be easy to work with)
    6-10 feet 3/8” clear plastic tubing
    1 each ¼” brass pipe tee
    1 each ¼” pipe to 3/8: hose adapter
    1 each pressure gauge 0-60 PSI or so – all you’ll ever need is 5- 10 PSI, so the gauge range doesn’t have to be high.
    1 each large rubber stopper – this is the hard part to find. It may take some searching to find one that is a snug push fit to the inside of the filler port on the master cylinder. You can use silicone rubber to seal a brass fitting to an old master cylinder cap, but they tend to leak too much.
    Home Depot or Lowes has some ¼” brass pipe stock that is continuously threaded in the electric lamp repair department, along with the brass nuts that go with it. This is better than a pipe nipple, since the nuts can be used to secure the pipe in the cap or stopper.
    OR if you can’t find the threaded pipe stock,
    1 each ¼” nipple, 1 ½”- 2” long

    The rubber stopper needs a hole drilled in it for the ¼” pipe nipple or threaded pipe stock. After you drill the hole, use some silicone gasket sealer to seal the pipe nipple as you push it into the rubber stopper. If you used the threaded pipe stock, use the nuts to secure the stock into the stopper.

    If you can’t find a suitable rubber stopper, an old master cylinder cap can be used. Drill a ½” hole in the center for the pipe fitting. Cut the brass pipe stock to about 1”- 1 ½” long, the exact length isn’t too important. Push it through the hole in the master cylinder cap and thread one nut on top of the pipe stock where it sticks though the cap. Put another nut on the other side of the cap to lock the pipe stock in place. Apply some silicone rubber gasket sealer to both sides and when it is dry, screw the ¼” pipe that sticks out of the top of the cap into the tee.

    Remove the sprayer hose and wand from the garden sprayer. You may find it easier just to cut the sprayer hose off short and connect it to the 3/8” plastic tubing. The idea is that the 3/8” tubing connects to the pickup tube inside the sprayer in a reliable, leak proof fashion. Another alternative is to remove the spray nozzle from the end of the spray wand and connect the 3/8” tubing to the wand. This leaves the hand valve in place and may be useful to start/stop the flow of brake fluid.

    The 3/8” plastic tubing connects to the pipe tee using a push on hose barb type adapter. The pipe tee has one port for the gauge, one for the 3/8” hose and the other to connect to the rubber stopper or master cylinder cap that you modified.

    Fill the pump sprayer with a quart of brake fluid. Set the garden sprayer on the ground and screw the pump handle down tight, and pump until brake fluid fills the plastic tubing. Then put the modified stopper or master cylinder cap on the master cylinder and pump slowly to make sure that nothing leaks or pops loose. No leaks, continue pumping until you get 5-10 PSI. Put a 6”-12” length of clear plastic tubing on the bleeder ports. Then open the bleeder ports on the wheel cylinders one at a time and bleed until the bubbles are gone. I use a 2 liter soda bottle with a coat hanger to catch the fluid . DO NOT REUSE THE OLD BRAKE FLUID. Repeat the process until you have finished all 4 wheels. You will have to pump the sprayer several times to maintain the 5-10 PSI needed to do the job. When finished bleeding, loosen the pump handle to relieve the pressure, remove the stopper/modified master cylinder cap and test the pedal.




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