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

[99 Boxcutter]

So, my brakes are doing this thing where the pedal becomes rock hard after a few miles and completely locks up, rendering the car undrivable. I have to wait an hour or so until the brakes go back to normal.

Porsche dealership says it's *MOST LIKELY* the brake booster leaking onto the master cylinder and they want $2,300 to fix it which sounds insanely high because I went onto youtube and found THIS VIDEO where the guy made replacing those parts look fairly simple.

I'm wondering if I should try this myself or take my car somewhere else, but I'm worried about the dealership's diagnosis because they said they weren't completely sure until they dove into it. I'd hate to replace these parts and have the problem persist.

[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.

[Gelbster]

Just ask here for a referral to a competent, honest Indie near you. It may save you $$$$

Originally Posted by 99 Boxcutter

So, my brakes are doing this thing where the pedal becomes rock hard after a few miles and completely locks up, rendering the car undrivable. I have to wait an hour or so until the brakes go back to normal.

Porsche dealership says it's *MOST LIKELY* the brake booster leaking onto the master cylinder and they want $2,300 to fix it which sounds insanely high because I went onto youtube and found THIS VIDEO where the guy made replacing those parts look fairly simple.

I'm wondering if I should try this myself or take my car somewhere else, but I'm worried about the dealership's diagnosis because they said they weren't completely sure until they dove into it. I'd hate to replace these parts and have the problem persist.

[bwdz]

You need to diagnose what is wrong first not just replace everything and certainly this is an easy do it yourself with basic tools and not a $2300 job. A very hard brake pedal, works at first and then gets hard, is often a problem with the booster and not the master cylinder. It is possible that it is just the check valve since you have brakes at first. Never messed with the booster on the Boxster so I don't know where it is but I am sure someone here does.

[99 Boxcutter]

Originally Posted by Gelbster

Just ask here for a referral to a competent, honest Indie near you. It may save you $$$$

Sounds good to me. Where do I find one of those?

[mikesz]

You don't say the year of your Boxster. The pre 2000 cars had an issue with water getting into the booster and rusting it out. Water would get into the rubber bellows between the bulkhead and the booster. I had this problem on my 99. You have to drain the brake fluid completely, remove the master cylinder and the booster. I chose to replace the booster and the master cylinder while I was in there. I also purchased the retro fit kit from Pelican so I wont have this problem again. I would say it is impossible to successfully do this without having the Porsche TSB and you must follow it step by step! also, instructions would have you replace the aluminum bar that connects the brake pedal to the booster. I did not do this there are ridges on both sides of the rod that the bellows fits into I got my dremel and machined the ridges off because the ridges are not needed with the retro kit. basically the retro kit isolates the brake pushrod from the bulkhead to the booster so no water will ever get in. I found my brakes locking up at red lights I have a tip and there was no creep found with an automatic. I disconnected the vacuum hose to the booster and stuck my finger in and found the water. PM me if I can be of any help.