zach,
Lots of people seem to have problems with effective brake bleeding. I've run a British car business for a long time and I have seen actual paid, otherwise competent, professionals have a hard time with it too. From watching them I've come to the conclusion that the problem isn't one of understanding, but one of communication.
When you have specialised equipment( pressure or vacuum bleeder) it isn't too much trouble because the person doing the job is working alone and doesn't have to coordinate with anyone but him or herself. Two person bleeding requires good back and forth communication and coordination between two folks who may not understand what the other is saying, thinking, or doing. This invariably means air in the system, and an unsatisfying result. The first thing you have to do is to establish some agreement, or convention, as to terms and actions. Next, you need to divide up the jobs. There are two jobs. One I call the wet man. This is the one who works the wrenches and determines the results. The wet man is the one who will get the most exercise, but is also the COMMANDER! The other is called the pedal man. His (or her) only job is to push the pedal down when told to do so, and to release the pedal when instructed. You cannot have two bosses and get this job done properly, believe me. Here's how it's done:
First, the pedal man sits in the car and agrees that he will only do what the COMMANDER (I'll bet that's you) tells him to do, and to call out in a clearly audible voice each time he has completed that function.
Second, The COMMANDER fills the master cylinder with fluid and determines whether or not he wants to bleed the master cylinder in place. Frankly, I have found that this is rarely needed if you do the rest of the job correctly. Many folks resort to it after having limited or no success with wheel bleeding. That's because of the lack of communication I'm writing this long-winded diatribe to address.
Third, the COMMANDER (hereinafter no longer capitalized lest your HEAD needs bleeding) goes to the wheel furthest from the master cylinder (no doubt the right rear in this case), and positions himself comfortably so as to see clearly what is coming out of the bleed fitting. Put a pan and/or rags under this location to catch the outflow. No, I don't reccomend a hose or a jar or any other paraphenalia. These will only serve to get in the way and eventually keep you from closing the bleed screw promptly, which is crucial to success. Now you will begin to see why I call the commander the "wet man". When you are positioned correctly, with plenty of light, open the bleed screw and call out the single word command, "DOWN!" Now, the pedal man pushes the brake pedal down with a smooth, firm, relatively forceful stroke. This is done in one motion, as far as the pedal will go. When the pedal has reached the extent of its travel, IT IS HELD THERE. You listening, pedal man? Once the pedal has reached bottom, the pedal man waits a half second and calls out the single word, "DOWN!" He does not let the pedal up now! he holds it there firmly and awaits further instruction.
Now the wet guy closes the bleed screw and when it is gently but definately closed, he calls out, "UP!"
Next, the pedal man waits about a second, and gets his foot the heck off the pedal! When he has determined that the pedal has reached its highest position (with his or her eyes. Don't you touch that sucker) he waits about two seconds and echos the command, "UP!" The one or two seconds gives the master cylinder time to "equalise" and replenish fluid from the resevoir into the operating cylinder.
And so it goes. With each cycle the wet guy (the commander) observes the stream of fluid issuing from the fitting, and when it is nice and air free, he is done with that wheel. Of course he ends with the pedal down and the screw closed. Don't forget to then call "UP!" That's my most frequent mistake. It's always great to call for the down stroke on the next wheel and have the pedal man declare, "It's already down, Dummy!", or worse yet, to let the pedal up and then push it down!! He then moves to the next closest wheel and starts the process again.
A few pointers: Check the fluid level in the resevoir after each five or six strokes. I know this is more exercise than you were hoping for, but having to start all over again because of the cylinder going dry is far worse. Make sure the pedal man understands that at no time should he (or she) interpret your actions as any reason to lift off the pedal (or for that matter to push it down) ONLY YOUR ORDERS are a reason to act.
I DO NOT reccomend pumping the pedal at any time. This will only serve to agitate the fluid and thus introduce tiny air bubbles into the system, which will result in a spongy pedal.
Sometimes, before starting the process, it is helpful to open that furthest bleed screw and wait for fluid to start trickling out if the system has been dry. This will start the flow so that the very first stroke can start moving fluid through the system.
Also, I generally will go through the process twice. In most cases the second time through will not produce air, and only requires one or two strokes,but it gives certainty and peace of mind.
When the bleeding process is completed, have the pedal man apply very firm pressure to the pedal while you check for leaks and clean up fluid. The pedal man can also check to make sure that pressure is maintained in the system and that the pedal is firm and high, and does not sink. If it does, there is a leak or a master cylinder internal problem.
Once you master this system, try "anticipated preaction". Call out the "DOWN" instruction just an instant before actually opening the bleeder. This will prevent any inflow of air before the pressure begins to eject fluid. Likewise, try to start closing the bleeder just before the downstroke is completed. This also will prevent the inflow of air. It is especially helpfull once you've determined that you are just about finished with a given cylinder or caliper.
I know that a number of people reading this will have their own procedures and disagreements with mine. I have tried every procedure that I've ever heard of, and while this is the messiest one it is also the surest way to end up with an air free system. You must understand that when doing this job at home with an only partially proficient or interested assistant, it is vitally important to make the process as efficient and painless as possible in order to preserve peace and harmony. Be patient and understanding, and explain the need for the order of things. Otherwise I guarantee a fight. Also, the person doing the pedal can NEVER be the commander. T'won't work.
Yes, when you are working alone there are other methods. I've done the tube in a jar thing so many times I can do it while asleep. And yes, a vacuum or pressure bleeder will work well, though vacuum bleeders leave something to be desired and I've always had to finish up with an assistant to be sure of the result. The low pressure bleeder is a great piece of equipment, but a really good one is quite expensive. It's what we use in the shop because it saves man hours. But believe me, you can do every bit as good a job with the method described above. Just be prepared for the mess. Get plenty of rags and a couple of cans of brake cleaner in the pressure can. I'm sorry for the long post, but this isn't an easy thing to describe without actually demonstrating it visually. Give it a shot. It's all about communication. Good luck.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon