Flushing Brake Fluid?

[jaxx]

anyone have some good off hand information or a good link on how to flush and replace brake fluid?

want to hop mine up to 5.1 ready for the ring but its one thing ive never done? ive done the basics like bleeding but not a full on change

any special tools needed?

[Bibbs]

Google ;)

http://www.stoptech.com/tech_info/wp_howto_bleedbrakes.shtml

[jaxx]

tried that, just got a load of crap about seals going on a 74 chevy

ta anyway dude :)

[Bibbs]

Bleeding Process

1. Begin at the corner furthest from the driver and proceed in order toward the driver. (Right rear, left rear, right front, left front.) While the actual sequence is not critical to the bleed performance it is easy to remember the sequence as the farthest to the closest. This will also allow the system to be bled in such a way as to minimize the amount of potential cross-contamination between the new and old fluid.

2. Locate the bleeder screw at the rear of the caliper body (or drum brake wheel cylinder.) Remove the rubber cap from the bleeder screw – and don't lose it!

3. Place the box-end wrench over the bleeder screw. An offset wrench works best – since it allows the most room for movement.

4. Place one end of the clear plastic hose over the nipple of the bleeder screw.

5. Place the other end of the hose into the disposable bottle.

6. Place the bottle for waste fluid on top of the caliper body or drum assembly. Hold the bottle with one hand and grasp the wrench with the other hand.

7. Instruct the assistant to "apply." The assistant should pump the brake pedal three times, hold the pedal down firmly, and respond with "applied." Instruct the assistant not to release the brakes until told to do so.

8. Loosen the bleeder screw with a brief ¼ turn to release fluid into the waste line. The screw only needs to be open for one second or less. (The brake pedal will "fall" to the floor as the bleeder screw is opened. Instruct the assistant in advance not to release the brakes until instructed to do so.)

9. Close the bleeder screw by tightening it gently. Note that one does not need to pull on the wrench with ridiculous force. Usually just a quick tug will do.

10. Instruct the assistant to "release" the brakes. Note: do NOT release the brake pedal while the bleeder screw is open, as this will suck air back into the system!

11. The assistant should respond with "released."

12. Inspect the fluid within the waste line for air bubbles.

13. Continue the bleeding process (steps 11 through 16) until air bubbles are no longer present. Be sure to check the brake fluid level in the reservoir after bleeding each wheel! Add fluid as necessary to keep the level at the MAX marking. (Typically, one repeats this process 5-10 times per wheel when doing a ‘standard' bleed.)

14. Move systematically toward the driver – right rear, left rear, right front, left front - repeating the bleeding process at each corner. Be sure to keep a watchful eye on the brake fluid reservior! Keep it full!

15. When all four corners have been bled, spray the bleeder screw (and any other parts that were moistened with spilled or dripped brake fluid) with brake cleaner and wipe dry with a clean rag. (Leaving the area clean and dry will make it easier to spot leaks through visual inspection later!) Try to avoid spraying the brake cleaner DIRECTLY on any parts made of rubber or plastic, as the cleaner can make these parts brittle after repeated exposure.

16. Test the brake pedal for a firm feel. (Bleeding the brakes will not necessarily cure a "soft" or "mushy" pedal – since pad taper and compliance elsewhere within the system can contribute to a soft pedal. But the pedal should not be any worse than it was prior to the bleeding procedure!)

17. Be sure to inspect the bleeder screws and other fittings for signs of leakage. Correct as necessary.

18. Properly dispose of the used waste fluid as you would dispose of used motor oil. Important: used brake fluid should NEVER be poured back into the master cylinder reservoir!

Vehicle Wrap-Up and Road Test

1. Re-install all four road wheels.

2. Raise the entire vehicle and remove jackstands. Torque the lug nuts to the manufacturer's recommended limit. Re-install any hubcaps or wheel covers.

3. With the vehicle on level ground and with the car NOT running, apply and release the brake pedal several times until all clearances are taken up in the system. During this time, the brake pedal feel may improve slightly, but the brake pedal should be at least as firm as it was prior to the bleeding process.

4. Road test the vehicle to confirm proper function of the brakes. USE CAUTION THE FIRST TIME YOU DRIVE YOUR CAR AFTER MODIFICATION TO ENSURE THE PROPER FUNCTION OF ALL VEHICLE SYSTEMS!

How Often do I Need to Bleed My Brakes?

In closing, here are a few rules of thumb to help you to determine the proper bleeding interval for your particular application:

1. Under normal operating conditions, and without brake system modifications, typical OEM braking systems have been designed to NOT require bleeding for the life of the vehicle unless the system is opened for repair or replacement. If you're just driving around town or on the highway to work, there is really no need to bleed! There are a few European vehicles which do recommend replacement on a semi-regular basis for other reasons though, so be sure to check in your owner's manual or at your service center for your particular application.

2. Those who choose to autocross or drive in a sporting manner may choose to upgrade their brake fluid and bleed on an annual basis – this is a good ‘start of the season' maintenance item for low-speed competitors.

3. If your car sees significant amounts of high-speed braking, or if you choose to participate in driver schools and/or lapping sessions, bleeding prior to each event is a sound decision. More intense drivers at these events may choose to skip right past this step and on to #4…

4. Finally, dedicated race cars should be bled after every track session.

[jaxx]

so you still follow the same proceedure to actually complete change the stuff?

[Bibbs]

If you keep topping the stuff up you are then pushing the new through the lines .. it's why you go round in the sequence and do each corner and then re-do them ..

I'd suggest the first corner takes the longest as you then bleed a lot of the old stuff out the res .. then the others are just the lines.

[jaxx]

so will the old and new not try an mix? and how do i knw when the new stuff is coming through ?

[cfc1]

If i remember correctly, you can use something like metholated spirits (It was a purple liquid we used to use in the good old days) and bleed it through all the breaks, the do the whole thing again useing the new break fluid, when the fluid is through all the system it can only be the new break fluis... sorted.