Brake time: Bleed, Flush, Fill not same: the master cylinder method forgotten?
September 22nd, 2018, 9:23 PM
#1
Brake time: Bleed, Flush, Fill not same: the master cylinder method forgotten?
There's allot of "wrong answers" out there so i want to remind who will read it 
Bleeding is not Flushing: they are different. And filling involves a little more challenge - despite what ads tell you.
Bleeding is only getting bubbles out of the system for the symptom of "soft pedal". Flushing removes fluid at the bleeder screw to remove old fluid (due to design, fluid from the line is "trapped" and has absolutely no circulation). Neither necessarily work for Filling.
For brake Bleeding: older mechanics say sucking at the Master Cylinder is superior and allot easier than all that per wheel fooling around: but the tool for it is harder and harder to find due to non-standard china plastic custom brake fluid resevoirs. obviously this doesn't do a brake FLUSH (to get new fluid in the caliper area - the only way is the bleeder valve - due to cost efficient but inconvenient design. The old tool (for older trucks) can be found if you look hard, the new one: maybe not at all. P.S. Ii'm not sure you can fill a completely empty system this way - but theoretically yes - the easiest cleanest way from the top, 1x only not 4x). Finally: it may not work on some models please don't take the old best method as a bible for your new "strange" car.
WRONG: The "One-Man Brake Bleeding" (advertised heavily for bleeding, the tiny 8oz bottle that costs a whopping $12) does not work on an "empty/dry system" (i mean the no suction bottle method): as anyone who's tried found out! Pushing the peda pushes fluid (air for empty sys) but letting go pulls the same ammount back (you get nowhere unless you open and close the valve, this requires 2 people). The alternate is using suction (15-20 continuous psi required at bleeder valve or at master cyclinder cap) - unfortunately tedious without a 2nd person or professional hands free system and extra lift to use. 8oz is kinda an insult for $12 (so small, delicate).
ABS designs can be a stopper (not on GM i think, and not usually in general). But you'll know if it is because you'll get nowhere fast and will realize your not seeing fluid pass. don't force pedal. try it with the car running, in park with bloks, outdoors
(note the topic of bench bleeding master is avoided: do that if your system is full and bled and your "only changing the master" (perhaps skipping bleeding if you can): but not if your Filling a completely dry system)
comments please: especially about sucking the master cyclinder with the right tool
Bleeding is not Flushing: they are different. And filling involves a little more challenge - despite what ads tell you.Bleeding is only getting bubbles out of the system for the symptom of "soft pedal". Flushing removes fluid at the bleeder screw to remove old fluid (due to design, fluid from the line is "trapped" and has absolutely no circulation). Neither necessarily work for Filling.
For brake Bleeding: older mechanics say sucking at the Master Cylinder is superior and allot easier than all that per wheel fooling around: but the tool for it is harder and harder to find due to non-standard china plastic custom brake fluid resevoirs. obviously this doesn't do a brake FLUSH (to get new fluid in the caliper area - the only way is the bleeder valve - due to cost efficient but inconvenient design. The old tool (for older trucks) can be found if you look hard, the new one: maybe not at all. P.S. Ii'm not sure you can fill a completely empty system this way - but theoretically yes - the easiest cleanest way from the top, 1x only not 4x). Finally: it may not work on some models please don't take the old best method as a bible for your new "strange" car.
WRONG: The "One-Man Brake Bleeding" (advertised heavily for bleeding, the tiny 8oz bottle that costs a whopping $12) does not work on an "empty/dry system" (i mean the no suction bottle method): as anyone who's tried found out! Pushing the peda pushes fluid (air for empty sys) but letting go pulls the same ammount back (you get nowhere unless you open and close the valve, this requires 2 people). The alternate is using suction (15-20 continuous psi required at bleeder valve or at master cyclinder cap) - unfortunately tedious without a 2nd person or professional hands free system and extra lift to use. 8oz is kinda an insult for $12 (so small, delicate).
ABS designs can be a stopper (not on GM i think, and not usually in general). But you'll know if it is because you'll get nowhere fast and will realize your not seeing fluid pass. don't force pedal. try it with the car running, in park with bloks, outdoors
(note the topic of bench bleeding master is avoided: do that if your system is full and bled and your "only changing the master" (perhaps skipping bleeding if you can): but not if your Filling a completely dry system)
comments please: especially about sucking the master cyclinder with the right tool
