Persistent Vacuum Pump Issue

[antoneloc]

About a month and a half ago I got in the car and before starting it up, the brake pedal was rock hard. Had to lean quite a bit of weight on it just for the push to start to work. A couple days later the ESB(?) light came on, so I took it to the dealership and suggested that there was a bad vacuum pump. After a couple days, they came back that the vacuum pump fuse was blown, replaced that, and returned the car. Seemed fine for a couple weeks, then the issue (hard brake pedal, no light this time) started coming back. It seems to only be a problem after the car was sitting for a while.

Returned to the dealership, where eventually they replaced the pump itself, claiming that it was operating, but drawing insufficient vacuum. This took two weeks. Picked up the car on Tuesday of this week, and as of this morning (two days later), the brake pedal is hard again. Seems to function just fine while the car is on, but if the car has been sitting for a while, i.e. overnight, the brake pedal has no give. Given the brand new vacuum pump, does this seem like a leak in either the brake or vacuum lines? Any one else had similar issue? 2.5T, AWD.

 

[5tinger]

Have had the stiff brake pedal occur on a few occasion and far in between. But only after the vehicle had been sitting for longer periods of time. Noticed this only happens in warmer weather. Functionality is normal though so I haven't really thought much of it..

 

[D.J.]

Was your car affected by the voluntary service campaign?

Very odd that you have the same issue occurring after replacing the vacuum pump.

 

[antoneloc]

Was your car affected by the voluntary service campaign?

Very odd that you have the same issue occurring after replacing the vacuum pump.

Don't think so, this is a MY2023 2.5T. Also now experiencing intermittent noise on startup that I can only describe as an electric whirring sound coming from under the hood that stops after a couple seconds.

 

[D.J.]

Don't think so, this is a MY2023 2.5T. Also now experiencing intermittent noise on startup that I can only describe as an electric whirring sound coming from under the hood that stops after a couple seconds.

This sound? First 25 seconds is the vacuum pump (I erroneously labelled it as "fan" in the video)

 

[antoneloc]

This sound? First 25 seconds is the vacuum pump (I erroneously labelled it as "fan" in the video)

Hmm, not quite that. Mine's more of a mechanical sound, and only lasts 3-4 seconds. I'll try to get a recording of it.

 

[Nkcmetro]

Hmm, not quite that. Mine's more of a mechanical sound, and only lasts 3-4 seconds. I'll try to get a recording of it.

Has this been corrected? My 2019 is doing this, started right after the turbo oil line recall was done.

 

[antoneloc]

Has this been corrected? My 2019 is doing this, started right after the turbo oil line recall was done.

Negative. They replaced the vacuum pump entirely and issue persisted.

 

[cameron03]

Negative. They replaced the vacuum pump entirely and issue persisted.

Did you find out what was causing the problem?

 

[Cowboymarc21]

Has this been corrected? My 2019 is doing this, started right after the turbo oil line recall was done.

I am experiencing the exact same issue. Never experienced the stiff brake pedal issue in 5 years that I owned my 2019 Stinger . I have even stored it over a winter.
I got the turbo oil feed line recall done and after a day or 2 of not driving the issue happens. Brought it to the dealer to diagnose/repair it.. and they are unable to find the source of the issue. This just reinforces my belief that one should avoid dealerships .