Originally posted by f.booth:
Hey you oldcarandtrucknut,
Out of curiosity, what is the purpose of bleeding the master cylinder that way? as opposed to just trying to bleed it all at once?
The short tubing hooked up to the master goes into a separate reservoir just like bleeding wheel cylinders? After it's bled, do you have to switch out that temporary tube real quick with the permanent line before all the brake fluid runs out of the master cylinder?
Because you'll have a greater chance of trapped air in the master if you don't bleed it first. Typical method is to bench bleed the master first. If the manufacturers directions say otherwise, then do that ( as in oldcarandtrucknut's case.) Most manufacturers say to bleed the farthest wheel first. As for the tube in the master, put the end of it into the resevoir, not a jar. Watch for bubbles there. After you bleed the master, don't worry about dripping fluid from the ports ( except to get it on painted surfaces.) Just don't let the resevoirs empty. The way I do it is bench bleed the master, leave the bleeder tubes on and bolt the unit into the vehicle. Then remove one tube and attach a line. Do the same with the next line. When I do these repairs out in the field ( I do this stuff for a living), I try not to bother other techinicians. So I usually gravity bleed everything. This might not be a luxury for you since the master is under the floor. So you'll need to grab a helper. The usual process is to have the helper pump up the pedal, then hold pressure. Crack the bleeder until the pedal goes all the way to the floor. Close the bleeder, release the pedal, apply pressure, crack the bleeder, repeat. Doing it one man is possible like others have mentioned with a tube and a clean jar. Best way is to pressure bleed but costs for the tools aren't justified for ocassional use.
If you are doing it by yourself, keep in mind that not much fluid is needed in the brake lines. So you won't need to use a complete container just for one wheel. It's a pretty small volume. Oh yeah, once you have a cylinder bled, tap it with a wrench or something. Crack that bleeder one more time and release any bubbles that might have been stuck to the cylinder walls.
