911uk

How can I test the Brake Booster?

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4 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHHow can I test the Brake Booster?

Leading reported evidence

Check brake booster and vacuum are all ok

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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 want to check my brake booster and vacuum are all ok but can't find anything in the workshop manual other than how to replace the booster.
Original post Read captured discussion
How can I test the Brake Booster?

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Leading evidence: 'Check brake booster and vacuum are all ok' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check brake booster and vacuum are all ok' (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.

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1 matching discussions · 4 captured posts examined · 0 partial discussions

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Replace booster

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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 want to check my brake booster and vacuum are all ok but can't find anything in the workshop manual other than how to replace the booster.
Original post Read captured discussion
How can I test the Brake Booster?

Run ate blue at the mo, probably switch

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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
Running ATE Blue at the mo, probably switch to SRF once I've used up the ATE.
Original post Read captured discussion
How can I test the Brake Booster?

Frequently discussed actions (3)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check brake booster and vacuum are all ok

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
I want to check my brake booster and vacuum are all ok but can't find anything in the workshop manual other than how to replace the booster.
Original post Read captured discussion
How can I test the Brake Booster?

Replace booster

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
I want to check my brake booster and vacuum are all ok but can't find anything in the workshop manual other than how to replace the booster.
Original post Read captured discussion
How can I test the Brake Booster?

Run ate blue at the mo, probably switch

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
Running ATE Blue at the mo, probably switch to SRF once I've used up the ATE.
Original post Read captured discussion
How can I test the Brake Booster?

Coverage and how to read this overview

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.

911uk: 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: 20261026T203514Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I want to check my brake booster and vacuum are all ok but can't find anything in the workshop manual other than how to replace the booster. Anyone know how to confirm all is working ok? Thanks...

POST 2Original post

Do you have any symptoms ? You need a special tester that can build up the vacuum to -400 to -600mbar in the brakebooster and then let it stay there. After a while you will read out the values and see if it is the same vacuum. To check if the vacuum pump is OK you will need a Porsche system tester. You can always have a look if you suspect a cracked vacuum line ?

POST 3 / ORIGINAL POSTEROriginal post

Thanks for the reply....Just want to check the booster so I can discount it more than anything else. Symptom is inconsistent pedal pressure which I believe is really to do with mild overheating of the brakes coming up to the first turn at the end of the main GP straight on the ring day recently. It's a hell of downhill and braking from 160 down to about 40 (I think!?) in about 170 metres. Not major but enough to be unhappy Now the cars got R888s on I've improved the cooling and will be fitting some upgraded pads and reflushing the fluid in the next few days. Running ATE Blue at the mo, probably switch to SRF once I've used up the ATE. Never overheated last year so I suspect I'm driving a little harder this year

POST 4Original post

which all like a heat build up and brake fade, like you said you are pushing much harder and there are a series of factors that will contribute to this including discs holes being filled with brake dust, brake fluid in the upper opertaing range, heat build up and the bumps on the track ceratinly dont help, etc

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