1 week of not driving +Flash rust = Grinding brakes?

Living in the city, I only ever get to drive my car from Friday night to Sunday night. Over the last month or two, I have had a troubling occurrence with my brakes. Every time I move the car, after it has been sitting for a week, I need to give the accelerator a tap to break the lock or bond that has occurred between the caliper and rotor. When I get out, I can see the distinct outline of my caliper on the rotor. Then, for the next 20 miles, the brakes grind something fierce, lessened by my accelerating and wailing on them a few times. This last weekend, an almost deafening whine came out of the left rear, so much so that someone actually stopped me and told me they thought that I had a problem. The sound went away after I did the wail on the brake fix. I have heard that Porsche brakes need to warm up a bit, but does anyone else have these sort of extreame issues with their brakes. I am going in to have a tech inspection this weekend, so I get a better look over the weekend.

They will do it in a weekend, let alone a week, especially if you put it away wet, or it rains. I scuff off the rotors going down the driveway. About a half a mile later everything smooths out. The rear brake noise should be looked into. If you can put the car away on a flat surface without engaging the park brake, that may help a bit. IE turn it off and leave it parked in gear, no park brake.

The rusting is normal when wet. However, taking 20 miles to fix the "grinding" noise is not normal at all. The first good application of the brakes should clean them completely. Additionally the noise from the rear is also not normal. You have the car looked at.

The rust is normal, but the time its taking you to clear it off is certainly not. Usually by the time I get to the end of my street (hill) my brakes are clear, even after prolonged periods of sitting. How's your braking once the rust has been wiped clear? Off Topic: My tires also get a little flatspotted from sitting for a while. Makes for a fun drive down the driveway on a cold morning when you combine cold engine, rusty rotors, flatspotted tires, and cold tranny. :-)

It takes a while for the rust to come off my rotors too. I can usually hear a slight grind from the rust for at least the first ten to fifteen times I apply the brakes after that there may be a little rust that is visible but does not produce an audible grind. So I always drive it back and forth a few time in the driveway after washing it to remove the water that causes the rust. It usually stops most of the rust from forming. The old ounce of prevention....

Well, its new pads and new brake fluid all around! Worn pads are what they say is the cause of my issue. As I have several track days this year, I am changing the fluid as well. They didn't take all the wheels off, so I wouldn't be surprised if there is something else. Car goes in over the week. This track stuff is starting to add up. I really need my own garage!

Rusting when you park for any significant period of time is normal - the time for it to clear depends on your driving style. Around town I cruise and caress the brakes and it can take two days to clear. Out of town, two good hard 200 to 50 kmh decelerations will clear anything..... ....but I agree with the advice on the handbrake, leave it off if you can.

What a timely thread, as I was just pondering the same thing after putting away my car wet over the weekend. A loud pop came from the rear wheels this morning as I nudged the accelerator after releasing the e-brake. After some rust-scrubbing of the brakes while pulling out of my neighborhood, the grinding sound disappeared and the brakes were fine. As many of you have mentioned, the rust on the rotors from the wetness is normal. Can I assume then you wouldn't need to drive it immediately after to scrub off the rust? Is there any harm in letting the rust sit until the next time you drive the car, say in a week? Thanks for the advice.

The longer it sits the longer it will take for the scraping noise to disappear. I have seen no long term effects.

chris, I am usually on the same schedule as you are. It sits garaged for most of the week and then on weekends I take her out... I haven't noticed anything as severe as you mentioned though. OT: It was nice meeting you at the Pocono's a couple weeks back. Love the 996

Guys, I am having the same issue with disc brake surface rust on my 02 C4S. If the car sits for more than two days, the handbrake gets stuck, and I need alot of throttle to get it dissengged for the first few feet. Then there's loads of squeeling noises from the pads & discs. After driving/softly braking for 5-6klms everything is normal. Whats wrong with the handbrake ? Anyone else experienced this ?

Exact same thing here, drive the car maybe once a week. If it's put away wet (right after washing it for example), i need quite a bit of throttle to break free. To make matters worse, the garage it's parked in can get pretty chilly. Last week, only one of the rear wheels released for the first couple of feet! In any case, by the time i get out of the parking garage (which as a few steep ramps), the grinding noise is pretty much gone.

I've read in an older EVO magazine that the same thing had happend to their 986S. Their local dealer knew the problem but not the solution. Could it be that the parking brake seizes ?

Just depends where you park it....if it's cold and outside, you will notice the problem more. As for the parking brake, it's not a bad idea to leave it disengaged so as to prevent that rear wheel sticking because the rotors 'corrode' onto the pads and that's why it may take a little throttle to 'unstick' it. Either way, it's not big deal, but you can minimize these effects by never parking it wet, or getting the brakes nice and hot before parking it in the garage. If you're outside, there's not a lot you can do but just deal with it.

As I do (and always rec'd when asked) is to NEVER use the p-brake unless it is absolutely needed. Use your car in gear when you shut it down.

Looks like a common problem, I have the same issues. After the pop I hear the grinding and it disappears about 2 mins later. Have not felt any long term effects yet.

before i put it away wet, i just ride the brakes a little when i get onto my street. problem solved. same thing when washing it. take a quick spin down the street and ride the brakes pulling into the garage. gives them a little heat and a good squee gee effect.

Don't worry about it, just drive more often. Rust happens between the time I wash the car and the time I get back outside after a shower to drive the car (on all types of cars I've had).

Rust is something that happens on almost all cars after they've been washed. This is a diffenernt case though. There is severe squeeking and disc pad contact. I also hear the same noises (hhhrrrshh hhhrrrshhh hhhrshhh repeat as needed !!!) Above all though is the handbrake been completely stuck.

I think the pop you here after parking with wet brakes is the pads rusting to the rotors, not the parking brake.

Thats right, its not the parking brake. There's this big 'THUMP' from the rear disc area as you release the clutch to reverse out. Nothing happens until the force built up from the power to the wheels breaks the rusted bond that has formed between the rotor and the pads-and it suddenly lets go. The first time I thought I'd broken something! It only happens if the car sits more than a week though.

I hear the clunk as well in week long outdoor parking. I assume it's a combo of cold moisture, cross drilled rotors and rust.

Again....normal. Indeed, all of my cars have had this tendency. Drive more. Ride the brakes before parking when wet if you park in a garage; else it really doesn't matter.

On our cars I believe the e-brake is an entirely separate brake mechanism from the disc brakes and rotors. It's another brake on the inside of the wheel (a drum brake?). A redundant system, so that if your disc brake fails there's another brake to slow the car down. The pads may be sticking to the rotors, but the e-brake is something separate. FWIW, I have the same problem after I wash the car, but it goes away after 1-2 applications of the brake.

The parking brake is separate from the rear disc brakes. It is a drum brake inside the top hat. Our discs can rust in 12 hours if put away wet. After washing the car or driving in the wet. heat the brakes up before parking. Drive at a normal speed. Brake lightly then put your foot on the gas a drive with the brakes on (lighty) for a minute. Then park. Note, brakes first then foot back on the gas else the e-gas system on 2000 and newer cars will shut down the engine. If left to rust for a week or more, it can take a lot of power to break the bond between the pads (which have metal elements) and the rotor. This can cause a brake warning light to show up temporairily.