Porsche dealership want $2,300 wants to replace brake booster and master cylinder

[Paul]

Are you losing brake fluid (is the level is going down in the reservoir)?

[dghii]

Originally Posted by Paul

Are you losing brake fluid (is the level is going down in the reservoir)?

Perfect question!! Your booster will not leak into the MC. Your MC will leak into the booster.

I have not had this issue with my Boxster. I have had it with my 30+ year old Alfa Spider.

My symptom was slightly different. I would not have any power assist to my brakes when starting my car. After the car built vacuum, I did have boost. Eventually, over a few years. the problem got worse and I noticed low level of fluid in the MC. The leak got bad enough that I new I had to replace the MC. I also found to about where my fluid was going and I ended up replacing the brake booster at the same time.

Again, I would experience lack of power assist. My brakes did not lock up. Brake systems have not changed much over the years but your Boxster has ABS while my older car did not. ABS is suppose to keep brakes from locking up but I have no idea what their failure mode is.

[Paul]

The next step is to read the ABS codes.

[bwdz]

Guys, a leaking master cylinder will not cause a stiff pedal but rather a spongy pedal. His issue is in the booster or the check valve. No abs codes for that or the dealer would have mentioned replacing that as well.

[Paul]

I've never known a failing booster or check valve to lock the brakes....I'm assuming "completely locked up" means the car cannot move.

Read the codes. I'm assuming from the OP's post that he has called the dealer and has not taken the car in yet.

[78F350]

One of my '99s had a brake pedal that started to stick. Sometimes I had to pull it up with my toe to fully release the brakes. Not the same problem, but it led me to a couple good threads on Renntech.org.
This one seems to be the one for you:
https://www.renntech.org/forums/topic/42415-replaced-brake-booster-causes-grown-man-to-cry/

Here's the DIY thread that I found and fixed my problem with a booster from my '01 parts car:
https://www.renntech.org/forums/topic/15633-brakes-not-releasing-sticking/

[Lew]

The most obvious cause for a hard pedal is simply not enough vacuum. Any brake booster requires a minimum of 18” vacuum to operate efficiently. Anything less than that will contribute to the pedal being harder to push. Check the vacuum hose to the booster.....Could be leaking!

[bwdz]

Originally Posted by Paul

I've never known a failing booster or check valve to lock the brakes....I'm assuming "completely locked up" means the car cannot move.

Read the codes. I'm assuming from the OP's post that he has called the dealer and has not taken the car in yet.

We read his post and understood it different, I read that his pedal locks meaning impossible to push, you read that his brakes lock.

[Paul]

78F350's post nails it. Bleed the brakes. The dealer is likely correct in suspecting a leaking master cylinder which can leak into the booster.

[99 Boxcutter]

Originally Posted by Paul

I've never known a failing booster or check valve to lock the brakes....I'm assuming "completely locked up" means the car cannot move.

Read the codes. I'm assuming from the OP's post that he has called the dealer and has not taken the car in yet.

I took the car to the dealership. It's still there. Should I ask them if there's any codes?

[Paul]

No need, I'm pretty sure they did that already.