Replaced booster, bled, bled & bled again, still almost no brakes

[98BoxsterRehab]

After replacing the booster I bled two large bottles of DOT4 fluid through all of the calipers and clutch. Clutch works great but I have to pump like mad to stop on the road. Pedal goes to the floor on the first two pumps. Takes five pumps to stop the car at low speeds. Noticed that when I have the auto-bleeder hooked up at 20psi on a full resivoir I don’t have to pump quite so much. Prior to replacing the booster the brakes were hard as a rock - pedal hardly budged, but stopped the Boxster every time. Post booster replacement I was expecting more give but something is seriously wrong here. Need help to know how to debug this. What remediation steps should I try and in what order?

[JFP in PA]

You probably have air in the ABS/PSM control network, which requires a software activation while bleeding to get it out..........

[98BoxsterRehab]

Thanks for the response. I am not an expert - soooo - if an expert person can advise precisely the options on how this can be accomplished that would be greatly appreciated. I have read posts that the Durametric Tool is a consideration but before plunging that kind of investment into bleeding the ABS block, hoping that a link to a step-by-step might be shared to help ensure that my meager funds aren't wasted. Perhaps thare is a "poor-man's" work-around?

[Brian in Tucson]

Before buying into Durametric, maybe you can call an indie Porsche shop and ask if they can bleed your brakes. Cheaper than buying Durametric, and more likely to solve the problem.

[mikefocke]

Originally Posted by JFP in PA

You probably have air in the ABDS/PSM control network, which requires a software activation while bleeding to get it out..........

Ah...a new acronym ABDS doesn't stand for the Atherstone Binge Drinking Society in this case but for ????

[JFP in PA]

Originally Posted by 98BoxsterRehab

Thanks for the response. I am not an expert - soooo - if an expert person can advise precisely the options on how this can be accomplished that would be greatly appreciated. I have read posts that the Durametric Tool is a consideration but before plunging that kind of investment into bleeding the ABS block, hoping that a link to a step-by-step might be shared to help ensure that my meager funds aren't wasted. Perhaps thare is a "poor-man's" work-around?

The ONLY way to do this is with a Porsche specific scan tool.

[tonythetarga]

I’m thinking it should be ABS. The D and S are next to each other on the keyboard, at least on my phone. ...considering all the great free advice JFP posts, typos shouldn’t count. 😎

[mikefocke]

I'd allow him a hundred typos.

I collect acronyms and it bothers me if I don't know one so I look it up. And then not finding it I ask so I can add it to a Porsche specific acronym list I maintain.

[CASair]

don't you need to pressure fill them with the ABS unit? I know Audi's do. you can't get all the air out the old fashioned way.

[JFP in PA]

Originally Posted by CASair

don't you need to pressure fill them with the ABS unit? I know Audi's do. you can't get all the air out the old fashioned way.

We use pressure bleeding/flushing exclusively.

[CASair]

sounds like the OP is working on a budget from his own garage? not sure.

[JFP in PA]

Originally Posted by CASair

sounds like the OP is working on a budget from his own garage? not sure.

Really doesn't matter the budget or the location, some projects simply require certain tools, and there are no realistic ways around that.

[FireCayman]

Question to the OP, did you bleed both sides of the calipers in each corner?

A few years back I flushed my system and had the same exact symptoms after attempting to bleed my brakes. Read on a forum to bleed both valves on each caliper and like magic they stopped on a dime after that procedure.

If not what everyone else said above.