I got the dreaded malfunction warning yesterday...

 

How many miles?

 

~4700, about 3500 of which are highway. No track use, but I did take the car to the Maryhill Loops, which was probably the most fun, spirited drive I've done...

 

We thought our yellow one was fixed but hubby has had the warning a few times since the service. It's at 5130+ miles as of tonight. It'll be going back soon...

I just looked up Maryhill Loops. WOW that looks like something you'd drive in Europe!

 

Test road built in 1911. Another photo: https://en.wikipedia.org/wiki/File:M...d_from_air.jpg

The loops were an absolute blast. My best time was 2:32. I suspect someone who knew what they were doing could do a lot better.

Will report back on my e-brake malfunction.

-mark

 

I got the dreaded malfunction three times last week. Was in the shop over the weekend and $1,500 in parts later I have the car back. So far on the drive home no problems but haven't driven it since.

 

Hey did you go with dream drives for kids? I was in the first group. I did 2:18-19, it is amaaaaazing!

 

Dealer checked the yellow car yesterday. Turns out the problem is that the parking brake may not extend the pad enough to fully contact the rotor, which means in our case we may think the brake is engaged but in reality it's not!

We are okay to drive the car until they get a part (not sure the exact fix) - but were told not to trust the parking brake and don't leave it on a hill in park without also putting it in gear.

This is really good to know because our driveway goes down a hill to our house. We often pull in and engage the parking brake to get the mail, and even though it's fairly level (depending on exactly where you stop) the car could still roll if the brake didn't hold.

Originally we had an appointment closer to the end of the month but every time hubby drove it he was getting multiple faults so they asked us to bring it in ASAP. Glad we did.....having a car roll away when you think the e-brake is on would be quite a surprise.

 

Dealer simply reset my fault notice and I haven't had a problem since. It has been 2 weeks since I took it in.

 

So far so good in my circumstance

 

I was expecting to have a report today, but I just got a call from my local dealership claiming that the tech is working on two cars and will not be able to get to my car today. My appt. was setup a month in advance and this was the earliest they could get me in - they didn't seem to care if the brake was damaging the car in the meantime.

-mark

 

Hi guys.... I have been battling on & off with the parking brake issue for past year. I have PCCB brakes on my GT4. The problems started shortly after I bought the car and usually the car displays an error on dashboard and indicating parking brake failure. Usually the erro shows up as I try to disengage them manually or automatically. In addition at times the parking brakes sounds loud while engaging or disengaging but without throwing a code. I have taken it to Porsche dealership 3 different times complaining about the issue. The first couple of times, they found a calibration fault code and the fix was to adjust the parking brake shoes and perform a new calibration (all done under warranty). The parking brake would work ok for a little while then the error comes back. This week, I brought the car for various small nagging items but also included the issue with the parking brakes again. My Porsche mechanic who is also a good friend decided to dig deeper into this as none of the earlier fixes resolved the problem fully. So he took the wheel, brake assembly apart, then he called me indicating that he discovered so many little rocks present around the pad & drum & some trapped between the brake shoe and brake drum (disk) ( see pictures below). His conclusion the excessive presence of the rocks is interfering with the operation of the parking brakes and also is throwing the calibration off.
Of course the next question is this a warrantable case, and the short answer from PCNA is "NO". Now comes the cost to repair the damage.... well Porsche does not sell this braking drum located in the center portion of the rotors separately and you must buy the entire rear PCCB rotor assembly which is $6000 each for just the parts. I believe it is made of Aluminum or perhaps magnesium and is a separate part from the actual carbon ceramics rotor but unfortunately Porsche does not offer it separately. There is no way Iam going to pay $12000 for parts and probably another $500 to $1000 for labor.

I figured the main brake functions are not affected and I can live with the occasional parking brakes errors, plus I am better off spending half of this money and change the brakes to steel which is what have been wanting to do as I hate the PCCB brakes during cold wet weather of the Northwest and they are harder to modulate on track than the steel brakes.

This afternoon and after leaving the dealership disappointed I asked my friend who owns a GT4 with PCCB if we can remove his rear rotor and examine it at my shop. Guess what he shows the same exact wear as mine and he too has been complaining about the parking brake error messages. After further inspection and taking few measurements I came to the conclusion there is plenty of material thickness, and I can put this parking brake drum on the lathe and take a small clean up cut and bring it back to new condition, but will take it dealership to recalibrate it. I think you are supposed to maintain 2 mm gab between pad & drum. This will cost me few dollars and will fix the problem but there is no guarantee it won't happen again, but the process can be repeated again and I am not too worried about the drum being too thin since it is only used during parking. I am also confident we can probably machine in my shop a brandnew replica replacement part for very low cost.

I figured I should share this with you in case others are still getting these error codes. I believe my situatiin is more common scenario since I found my friend car has the same exact issue, and I suspect most Porsche delears are focusing on the module or its calibration versus looking into mechanical tear & wear. Regardless hopefully this helps some of you. Mark

 

Please see below

 

Wow that's not good. How is it that Porsche is having these issues and other manufacturers are not? My DD Volvo has electric parking brakes and at nearly 70k miles I haven't had an issue and my car is driven in gravel regularly.

Allowing small stones to build up in there sounds like a design flaw but the only way it will be covered is if it becomes a common issue.

 

I had the same problem all last year (I don't have PCCB) and they never could find the cause. They wanted the car to check all ground points and additional things which I never did....Around end of 2016 the fault stopped and I haven't seen it since...hopefully it will stay that way. Could be a tolerance/clearance issue like yours. No strange sound or anything since it stopped but I would remember when it happened that the emergency actuators would sound like off-phase....not in unison like they do now.