AhsanU

Due to the snow storm about a week and a half ago or so in the northeast, I couldn't drive my 991.1 GT3 for a while. I purchased a set of winter tyres to throw on and enjoy during this cold season this afternoon after not driving the car for about a while. I started it a few times during the week, but couldn't drive it as my driveway was snowed in. The car started fine and everything seemed copacetic.

Since the snow had melted today from rain, I decided to put the snow tyres on as well as the 991.2 steering wheel today. Immediately I noticed that the brakes felt off. I had to apply quite a bit of force to get any actual braking going. The pedal felt stiff and there was very minimal braking power. As I drove more and more to the service center, the car seemed to brake slightly better with each application. After picking the car up from the service centre, the brakes felt somewhat okay. After leaving it outside for about 4 hours, they're back to where they were this morning - they squealed hard upon first use, and feel very stiff with minimal actual brake force even when adequate pressure is applied.

Anyone know what's going on? Is this normal for PCCB's? This is my first time owning a car with carbon ceramics, I'm not sure if this is worth bringing up with Porsche.

LexVan

Can't help your PCCB question, but, stop doing the starting the car and letting it idle on days you can't drive it. Worst thing you possibly do to your oil. Fuel dilution and condensation buildup. Bad.

AhsanU

Noted! I didn't let it idle as much as I just made sure the engine cranked over. At most it idled for about 45 seconds or so.

Petevb

LexVan

Still a bad practice. It's going to start. It can sit for weeks. If you're concerned, buy a Porsche battery maintainer and plug into your cigarette lighter.

AhsanU

Snow tyres are 245/35/20 front and 295/30/20 rears on stock wheels.

The issue with the PCCB's were there from the beginning of the day - as in when the summer tyres were on. So I don't think that's the issue.

ipse dixit

Mike in CA

I've never experienced what you describe with the PCCB's on my 991.1 GT3, and while there will be some difference in stopping distances between cold and warm brakes of any type, to have the brakes feel like you can't generate "any actual braking" with your PCCB's isn't normal under typical conditions. I've also never had my brakes squeal excessively, or really at all. That said, while I've driven in what passes for cold weather here in my part of California, I've never had the car out in truly frigid weather like you get in the Northeast so take that into consideration.

AhsanU

I should reiterate that I drove the car while we were experiencing 30-15° weather quite often before today and there weren't any issues with the brakes. I drove the car every day. Is it normal for this to happen to the PCCB's after not being driven and being in extreme cold climates? My garage temp literally dropped to 0°F at some point.

Para82

I have put 97,689 miles on my PCCB over the last decade and have never experienced any kind of issues like this whatsoever.

Edit - My car also sat for months at a time on several occasions while I was out of town.

scb997

PCCBs can be pretty bad when cold and wet. I've had a few "surprises" when I've started to apply the brakes and not much happens. You end up pressing VERY hard for light to moderate braking. There's NWIH you'd be able to brake hard enough for anti-lock to kick in, for example.

It seems to be the worst when it's just above freezing and things are wet. I have not associated this with whether or not I've driven recently. Only with the current conditions.

So, you need to "manage" PCCBs. By that I mean, on cold/wet days, try to anticipate this until they've had a few miles to warm up and dry out. I'm sure that you could quicken the process with left-foot braking. But, I rarely feel that's necessary.

ipse dixit

ajw45

I think it's normal for cold and wet PCCBs. I've been surprised by the lack of bite a few times driving in the rain but that just seems to be on initial application and the brakes are fine with a little use.

SmokinGTS

I would take your car to the dealer and have this checked out, you may have a brake booster or master cylinder problem. This is not normal, they run these cars in Canada and Finland at the Porsche driving school without issues in super cold conditions.

Mike in CA

This. The OP's problem of not having "any" braking, not just a lack of bite, in cold weather sounds abnormal. Seems like something that one shouldn't guess about or take chances with.