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"You should find out the suggested bleeding order. Most vehicles suggest a specific order in which you are intended to bleed the brakes to ensure that air is efficiently evacuated from the system. In the absence of this information, you should bleed the back brakes first, and you should start on the driver's side; So for a USDM vehicle, you should bleed the rear left first, followed by the rear right, then the front left, and finally the front right."
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"The person in the car should push in the brake pedal and hold it down; Now you close the valve. If the pumper raises the pedal before you close the valve, some air will be drawn back into the system (or, if you're lucky, some of the fluid in your line) and possibly compromise your bleeding job. The tighter your clear line fits onto your bleeder fitting, the less likely this is to happen.
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Use a hose that leads vertically from the nipple bleeder to not only acquire a safe amount of back flow, but also to witness the extent of the air that is being pumped out of the system.
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The pumper can pump the brakes a couple times, and then with them up, you open it again. Repeat as necessary until the fluid comes out completely free of bubbles. The purpose of pumping the pedal with the bleeder closed is to unify the air bubbles in the system to aid in pumping them out. It sounds superstitious, but it makes a significant difference."
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Tricks and Tips
Sometimes air bubbles can get trapped in vertical bends in the brake line. That is, if the brake line has an up and down pathway towards the caliper air may refuse to pass through these areas. This is why when I start my bleeding process (especially when there is no pedal pressure) I try to do it very quickly. Slamming the pedal down forces fluid through the lines and can get the air bubbles to move, since they tend to climb back to the highest point in the line, you then have to close the bleeder and have the person on the pedal immidiately try to push the pedal down again... Do this quickly a number of times untill you notice a large amount of air leave the system, or when you feel it has been pumped enough times.
Infact, during this proceedure all you need to do is keep your finger firmly pressed on the end of the bleeding hose.. (or install some kind of one way valve that accomplishes the same effect) WHen the peddle pusher pushes down your finger will be unable to stop the fluid/air form leaving the hose, however, when the pedal comes back up, your finger will seal the flow of the hose and nothing will backflow. This way, the pedal pusher only needs to rapidly pump the pedal while you hold your finger on the end of the line (aiming a spray into a container of some sort)
This is where tools that push a constant flow through the system come in handy, since they are much less likely to break up air bubbles.
After this somewhat violent method, you can then slow it down and work out smaller bubbles more carefully, using the open/close up/down proceedure.
Always look for air bubbles in the resivoir before starting!!! It will do you no good to pump bubbles into the line. If you have bubbles in the resivoir you may have to slow down the pedal pumping, and wait for for the fluid to desaturate the air aswell.
