2007 TT, and I have a braking question
Over the past few months I will occasionally feel a slight pulsation in the brake petal when slowing from around 30- 40 mph to a stop. Nothing else unusual.
But I had to make a panic stop on the highway from about 65-70 mph with full depression of the brake petal, and the front end swerved rather quickly to the right, instead of staying in a straight line.
Does this signify a brake caliper issue?
Tires are new
Thanks !

 

The pulsation could be attributed to out of balance wheel/tire or slight warping of the rotors, most likely the rotors since it happens when you apply pressure.
As far as the right side push, it could be that your caliper is seized. Have you checked your tire pressures? Do your TPMS work ok? If you have a substantial difference in TP, that could be a cause as well.

 

A seized caliper could cause the rotor to warp as well as the brakes to pull, so the two symptoms could run hand in hand. The thing about the Porsche brakes is there are no guides involved, so that means a seized or set of seized caliper pistons. My Audi brakes all operate on guides and they are usually what get mucked up, not the pistons.

Alternatively, if you were on a worn road, the slight impressions on the road could catch the wheels and exert a pull. If the pavement was flat, that theory doesn't apply.

Ed

 

Sometimes if the brake is held on at stop lights after hard driving, track days, etc. The excessive heat where the pad touches the rotor can cause slight warping of the rotor. It shows up in the light pedal pressure upon braking, unde foot. I had this on my 05 997 that got a lot of track time. It had Brembo brakes, 14 inch rotors, 6 piston calipers. I took it to my tech. He put on some special VERY abrasive brake pads, had me drive it for 40 minutes making several hard stops. The pads smoothed out the warps in the rotors. We put the regular brake pads back on...no more issues, and I kept my foot off the brake pedal after hard driving from then on. But, as Ed said too, tire pressure, uneven road surfaces, etc can also cause pulling and pulsing. Usually if the front are out of balance you feel it in the steering wheel, and if it's the rears, you feel it in your seat. Your situation sounds like slightly uneven rotor surfaces on the front.

 

Finally got car to my indy. Warped rotors and worn pads - replaced and all better now !