All of a sudden brakes are stiff so I cannot get the car to start?

2005 PORSCHE CAYENNE

187,000 MILES • 3.2L • V6 • 4WD • AUTOMATIC

EFABIAN0

MEMBER
1 POST

To start the vehicle, you have to press on the brakes. All of a sudden brakes are stiff so i can't get the car to start. Warning brake proportioning is shown on dash. The car ended up starting but my shifter was locked and couldn't reverse, neutral, or anything. Shut the car off, brakes locked again and no start. Any opinion would help. Thanks in advance!

Apr 17, 2023 at 12:36 AM

STRAILER

✓Experienced Mechanic
55,554 POSTS

This sounds like the brake booster or brake master cylinder is going bad and not returning completely. Here are the instructions on how to replace the units to fix the problem. Here is a guide as well:

https://www.2carpros.com/articles/a-comprehensive-guide-to-fixing-automotive-brakes-locking-up

You will need to bleed the brake master before installing it. Please watch this video:

https://youtu.be/WDxvEQrMkBg

Check out the images (below). Please let us know if you need anything else to get the problem fixed. These jobs will overlap.

Images (Click to enlarge)