4 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHBrake Problem
Leading reported evidence
Disconnect vacuum
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
Disconnect vacuum from booster (plugging vacuum line to and from) and brakes are awesome - hook it back up and brake pedal is inconsistant (long, short, spong,etc) and not safe for the road.
Leading evidence: 'Disconnect vacuum' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Disconnect vacuum' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
I don't have a manual (probably get a 997 soon) and don't really feel like taking it to my "local dealer" as they are clueless and will just start replacing things (they make me mad!).
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
Purchased the car (99 C2) last year and haven't really had any trouble at all with it (sans replacing water rez).
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Disconnect vacuum
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
Disconnect vacuum from booster (plugging vacuum line to and from) and brakes are awesome - hook it back up and brake pedal is inconsistant (long, short, spong,etc) and not safe for the road.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
I don't have a manual (probably get a 997 soon) and don't really feel like taking it to my "local dealer" as they are clueless and will just start replacing things (they make me mad!).
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
4 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T035758Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Long and short of it. Purchased the car (99 C2) last year and haven't really had any trouble at all with it (sans replacing water rez). On a whim I take it to a PCA DE at No Problem near Baton Rouge LA along with my track Toyota Supra. Go for a session and 1/2 and notice brakes are really cooking and decided to call it quits - was first time in 996 on track (stock everything!). Drive it home and take to it work for a few weeks - notice brakes are getting worse and worse. Order pads, rotors and some ATE blue.
Make time to do brake job and everything is going to plan but cannot seem to bleed brakes. Order some additional fluid just in case and try again. Still no go (pumping, vacuum bleed and pressure bleed). Order new master cylinder from thepartsbin.com and put it on (bench bled no less). No better. Order new brake booster and put it on. Not really better but notice when car is OFF the brakes are good all the time and with car ON brakes are minimal most of the time. Disconnect vacuum from booster (plugging vacuum line to and from) and brakes are awesome - hook it back up and brake pedal is inconsistant (long, short, spong,etc) and not safe for the road. Problem!
I think it has to do with the source of the vacuum for the brakes (there doesn't seem to be a vacuum leak as car runs fine). I don't have a manual (probably get a 997 soon) and don't really feel like taking it to my "local dealer" as they are clueless and will just start replacing things (they make me mad!).
What can I check or replace next? I saw something about a check valve and pressure tank on the vacuum diagram on the engine lid. IDEAS? Class? Class? Anyone? I work on all my "rides" and have the necessary tools, equipment and information to most everything - I hated to ask this question but I am stuck without a book to help point me in the right direction. I have no problems with working on motorcycles or turbocharged monsters but I've met my match with the German engineering.
PS: The rennlist forum is great but the search didn't really have anything.
Thanks in advance!
Unfortunately I don't have the answer for you, however, I would recommend that you post this question at RennTech.org also. Renntech is usually much more technical oriented when it comes to the 996 and 986 than Rennlist. Many of the same people post at both sites but technical questions seem to get answered faster and more thoroughly at Renntech.
I have had a couple 996/986's catch air in the ABS block. The only way I could get it bled is with the Porsche system tester at the dealer. For some reason all the vac/pressure bleeding in the world will not dislodge the air. The tester has a built in bleed function that has the ABS unit build up it's own pressure and gets rid of the spongy pedal. Good luck
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