Mr. Slowly

Greetings! My name is Ken. I've been lurking for a while and had to pop in for a question.

I daily drive my car but I've noticed this winter that if I let my car sit over the weekend the brakes will stick when I go to set off. Freeing the brakes usually takes a minimal amount of effort. There's a muffled *thud* that sounds something like a mallet hitting the rotor and I'm off. I didn't think much of it until I had reason to let the car sit for 4 weeks.

I knew the car would be sitting for a few weeks and we had a single day that got into the mid 40s so I washed the car. I made sure to take the hose to the under carriage as best I could. Four weeks later I go to move the car and the brakes are super stuck. Worse than trying to set off with the e-brake up. I had to build the revs up to 3000 to get the car rolling. All of the sticking force freed at once. Once free, everything seemed fine. Down the road however, I noticed a vibration in the brakes. Warped rotors. I was hoping I'd frozen the brakes together hosing off the under carriage and the vibrations would subside after a few miles but they did not. It's slowly been getting worse, as warped rotors always do. I've owned the car for 18 months and the brakes have always been perfect up until this event. I took a temperature gun to the rotors after a couple drives and found that the front rotors and rear rotors were in agreement with each other, thus ruling out a stuck caliper.

I've never had a car with sticky brakes like this. I was hoping someone here might be able to shed some light on my situation. It looks like I'm getting some new pads and rotors this spring (always OEM) but I don't want to replace them without correcting a problem I may have.

My car is an '08 with 34xxx miles and I suspect all braking components to be original. The car is completely unmoddified. I drive mostly like a grandpa.

Thanks, guys!

pmptx

Have you pulled the calipers off to make sure the pins are well lubed. The sticink at the beginning may be the lack of lube. When they heat up the minimal lube is helping a bit.
Only thing I can think of.

Reckon

I'd inspect the entire area even going as far as taking the rotors and pads off to get a good look at them. The caliper itself may not be seized but it could be getting to that point. The rear calipers are somewhat prone to that.

freq

Sounds like the pads just rusted to the rotors. A quick drive should eliminate all the rust an the pads and rotors.

Furthermore, probably NOT warprd rotors but pad build-up on the rotors. Jack up the car, take off the wheels hit the rotors with a green 3M scuff pad.

Conedodger

I agree. Take it up to 40 mph and brake firmly to about 5 mph a couple of times without coming to a stop. Drive around the block after to let the brakes cool. I'll bet the vibration is gone. Next time, take the car for a short drive to dry the brakes before parking it.

zeroptzero

Just rust between the pads and rotors like listed above. Make sure the caliper slide pins are lubed, don't get water on the rotors prior to storage, and chock the wheels instead of using the parking brake while in storage.

My car has sat in storage for five months so far, I lifted each corner and turned each wheel by hand last weekend to reduce flat spotting of the tires, no sticking at all. I run Carbotech 1521 street brake pads, they are a ceramic based pad, less likely to stick to the rotor with rust.

Mr. Slowly

Thanks for all the helpful insights.

I gave this a shot. I'll have to drive a bit further to see if it worked but I couldn't detect vibrations while performing the emergency stops. It would be great if the fix was this simple. Encouragingly, I thought to check for hot spots on the rotor with my temperature gun and found none.

I'm glad you brought this up. Can you confirm that the slide pins are causing the issue I've pictured below? Would you have to replace the pads/rotors to lube the slide pins?

Driver rear:


Passenger rear:

freq

no.

cdelena

As mentioned, this is very common with wet brake pads that just bond to the rotors. Try to do a couple of hard brakings to dry the pads after washing and parking. I bet there is nothing more wrong than the moisture and your surprise at the situation.

zeroptzero

They should be done once a year as normal maintenance IMO, so regardless of the problem. If you had to go 2 years that might be fine but I do mine yearly. You don't have to remove the pads to lube the slide pins, but they may stick to the upper section when you swing it upwards and pop out on you. You should lube up the pad shims to keep them quiet while you are at it so do that at the same time. Lube the pad to caliper contact surfaces, pad to retainer contact surfaces, and pad to piston contact surfaces. You don't have to remove the rotors.