Brake Fluid Flush

Brake Fluid Flush

Republished from http://www.bullittarchive.com/

Because brake fluid absorbs moisture, you need to change your brake fluid about every 1-2 years. Depending on the brand of brake fluid you use, you may need to change the fluid more often. There are several different methods to bleeding your brakes. Each has its own advantages and disadvantages.

Below are some general guidelines to different methods on Flushing and bleeding your brakes

1. Hold the brake pedal while loosening the brake bleeder screw allowing fluid to be discharged, and then close the screw, let off the brake and repeat the process.

2. Use a type of suction device that inserts into the bleeder screw, loosen the bleeder screw and suck the fluid through the system.

3. Use some type of pressure unit that clamps onto the master cylinder and applies pressure to the brakes, loosen the bleeder screws and close off when done.

4. Use a one way check valve inside the bleeder screw called a speed bleeder. Loosen the speed bleeder screw and step on the pedal, fluid will come out but the check ball will keep air from entering back into the system when letting off the pedal.

The different methods are all similar in that you will need to open the bleeder screw to allow the fluid to be released. Regardless of the method you will make it easier on your self if you attach a hose from the bleeder screw to a container to collect the brake fluid.

Basic instructions on how I Flush and Bleed my brakes

Method with stock bleeder screws

1. Gain access to the bleeder screw starting with the right rear wheel (Because that is the farthest from the master cylinder).

2. Have someone pump the brake pedal a few times and then hold the pedal down with steady pressure. Let them know that the pedal is going to fall to the floor and for them to keep pushing down. DO NOT let up until told so.

3. Attach a hose from the bleeder screw to a container to catch the brake fluid.

4. When the brake pressure has been applied, loosen the bleeder screw.

5. After the brake fluid flow stops, tighten the bleeder screw.

6. NOW the helper can take their foot off the brake and pump the brake a few times and then go back to applying steady pressure.

7. Repeat the bleeding process of pumping, holding, draining the brakes and tightening the bleeder screw again.

8. Check the master cylinder fluid level often to keep from running out of fluid and allowing air into the system.

9. If there is air in the system you will hear or see the air in the drain tube.

10. You need to keep bleeding the brake until you stop getting air out or you start seeing new brake fluid being drained.

11. Now you are done with that wheel. You can tighten the bleeder screw back up and repeat the procedure at the left rear wheel.

12. Perform the same procedure on the front right wheel then the left wheel.

Few things to keep in mind

Remember to watch the fluid level
Make sure your helper keeps their foot on the brake until you have tightened the bleeder screw and have told them it is ok to let off of the brake pedal.
Brake fluid loves to eat paint, be neat and take your time.
Some people like to fill the bottom of the catch container with fresh brake fluid where the drain hose is placed at. This way if by accident the helper were to release the brake pressure before you have tightened the bleeder screw it would suck in brake fluid instead of air. (Will only work AFTER the line is full of fluid)

Bleeding the brakes using the Speed bleeders.

1. Gain access to the bleeder screw starting with the right rear wheel.

2. Attach a hose from the bleeder screw to a container to catch the brake fluid.

3. Loosen the speed bleeder 1/4 to 1/2 turn.

4. Apply pressure to the brake and fluid will be forced out of the piston and into the catch container.

5. Release and then apply pressure again.

6. Keep an eye on the master cylinder fluid level.

7. The reason you do not have to close the bleeder screw is because the speed bleeders have a check ball in them to keep from allowing air to enter back into the system.

8. When there is no more air or you have new fluid being drained then you are done with that wheel and can move on to the next wheel furthest from the master cylinder.

Note: You may have a small amount of fluid run out by the threads of the bleeder screw when doing the rears. Just wipe it off when you are done. I think it leaks some in the rears because you spend more time flushing them, because the lines are longer plus the first one you are running everything through the master cylinder reservoir.

NOTE: These are just general instructions to let you know what is basically involved in bleeding the brakes. If you do not feel comfortable doing maintenance like this then either have someone that is experienced help you or take it to a shop. This is not something that makes you go faster but instead something that makes you STOP. Make sure you know what you are doing.

The right rear will take the longest because it is the longest line and because you are running all of the fluid in the master cylinder through it also. Expect to run about 24oz's through the right rear. The entire flush and fill will take right around a quart of brake fluid; mine was 1 quart plus a couple of ounces to fill the master cylinder to the full mark.

I use a brake fluid from ATE that comes in a gold color or a blue color. I alternate between the two colors and this way I can easily tell when the old fluid has been flushed out.

Rear bleeder screws, stock screws are 11 mm's.

Front bleeder screws, stock screws are 10 mm's. Brake fluid is blue in color.

Old brake fluid has now been flushed and you can see the gold color brake fluid.

Be careful pouring the brake fluid in the master cylinder. If you spill any fluid wipe it up immediately and move the rag away from the car. The fluid on the rag will still start to dissolve the paint.

Speed bleeder on the right, stock bleeder from the rear on the left.

Speed bleeder uses a 10mm wrench and the part number is #639560 for both the front and the rears.