So I just replaced my pads and flushed the brake system using the motive brake bleeder. Everything worked pretty well. AFTER I completed the job I was going back over one of the how-to's on this site and read that you are supposed to start with the wheel set that is farthest away from the master cylinder. I read another article on-line that implied that was important as well. Of course I did just the opposite.
My questions:Why? and since I screwed it up do I need to reflush starting with the RR wheel?
You should always start farthest away from the master cylinder. Usually that means RR, LR, RF, LF. You're probably OK unless your tracking the car.
But if the pedal is soft, then yes you'll have to bleed it again.
Why? If there are bubbles in the further away lines, they can migrate forward on the upstroke of the pedal. Since you used the Motive pressure bleeder, probably less of an issue.
Having done RR, LR, RF, LF (remembering to do the outer bleed screw and the inner) you should also bleed the clutch.
In addition to this, on replacing the fluid you should also bleed the PSM/ABS circuit. This is done from the RR outer bleed screw but requires the use of a PIWIS to initiate the PSM bleed function.
Even though I bled them backwards they're still bled. The whole idea is to push out any bubbles and replace the fluid. So there shouldn't be any bubbles to migrate. I did bleed both valves on each caliper.
As far as bleeding the clutch? well . . . I don't have PIWIS so I guess that will have to wait. I'll look for some archive articles on that.
When
bleeding
your brakes you should move in from the furthest bleed screw as stated above: outer RR, inner RR, outer LR, inner LR, etc.
However, when completely
flushing
the system the order does not matter.
Nick - Although activating ABS was needed on older Porsches, I've been told by several Porsche techs that ABS activation (or the use of PIWIS) is not needed for current models. Do you have some authority to the contrary?
Good point. I did flush.
re PIWIS and the clutch slave cylinder.
This
article in the archive does not mention it so may I assume it is not required?
So, do you then agree that PIWIS is not needed for a routine bleed or flush per the shop manual?
BTW, kehr is not referring to the scheduled flush of 2 yr old fluid where the stale clutch fluid is also flushed. He, like me, tracks his car. I flush at least every 6 months and bleed more frequently. I don't bleed/flush the clutch each time as I believe it to be an unnecessary pita.
Agreed on the PITA thing.
