'15 5.0: Brake booster bleed-down time?

[jayel27]

I've had a couple of incidents with my new-to-me '15 5.0 that make me wonder if there is a vacuum leak or just normal operation. While parking my car for an extended period of time (2-4+ days), I've come back to a hard brake pedal. this requires much more effort to press on the pedal so that the vehicle registers brake input enough to start the car. this has happened here in the cold winter weather of Michigan, and I haven't noticed it happening every time. has anyone else experienced this?

 

[Kraig Wilkinson]

I've had a couple of incidents with my new-to-me '15 5.0 that make me wonder if there is a vacuum leak or just normal operation. While parking my car for an extended period of time (2-4+ days), I've come back to a hard brake pedal. this requires much more effort to press on the pedal so that the vehicle registers brake input enough to start the car. this has happened here in the cold winter weather of Michigan, and I haven't noticed it happening every time. has anyone else experienced this?

Fortunately I have not experienced that problem. Car sat for 4 months with no problems. Still had vacuum. I would suppose there is a leak.

 

[Kraig Wilkinson]

I've had a couple of incidents with my new-to-me '15 5.0 that make me wonder if there is a vacuum leak or just normal operation. While parking my car for an extended period of time (2-4+ days), I've come back to a hard brake pedal. this requires much more effort to press on the pedal so that the vehicle registers brake input enough to start the car. this has happened here in the cold winter weather of Michigan, and I haven't noticed it happening every time. has anyone else experienced this?

Fortunately I have not experienced that problem. Car sat for 4 months with no problems. Still had vacuum. I would suppose there is a leak. I have a 15 5.0 as well.

 

[Gahaha]

Mine does that randomly whenever it is cold. Sometimes parked for barely 8 hrs, sometimes even indoors in a climate controlled garage. Something with being exposed to the cold I guess....not sure but learned to live with it, like the drive shaft vibration in first 5-10 min if car is cold.

 

[Chad86tsi]

Happened once in the year and 22,000 miles that I have had mine, it was a cool night prior.

 

[jayel27]

If we are discussing cold start conditions, I experience a slight but annoying vibration for the first couple of miles. I had thought it was the tires flat-spotting overnight (Conti DWS06 all around), but now there is a thought that it is the driveshaft? would that be rubber couplers in the shaft that aren't flexing properly at colder temps?

I've only had the car since December, so a lot of these conditions are new to me.

 

[Genesisson87]

If we are discussing cold start conditions, I experience a slight but annoying vibration for the first couple of miles. I had thought it was the tires flat-spotting overnight (Conti DWS06 all around), but now there is a thought that it is the driveshaft? would that be rubber couplers in the shaft that aren't flexing properly at colder temps?

I've only had the car since December, so a lot of these conditions are new to me.

Usually you'll here a clack or clunk noise from the coupler or have rough gear transition in 1st and reverse. I have also had people say they have a vibration but only at very low speeds and takeoffs having delayed engagement with slight noise or vibration but it would need to be in rough shape I'd assume for that. Most likely a tire or band in the tire, also suspension components will create vibrations and that is everything from worn struts to ball joints and wheel bearings. Hope that helps.

 

[greekgeek]

I had the same problem, only after even one day sometimes. Dealer replaces brake booster and seal, problem solved.