My car is just seven months old. Last week, after having not used it for a weekend, I had a problem when I drove on Monday morning. I shifted to D, but the car did not creep, as it usually does, when I released the brake pedal. After a few seconds, I pressed the accelerator pedal gently and there was a frightening thud before the car started to move. I have also noticed lately that there is a mild squeak from the rear suspension the moment I sit in the car. While I am of above-average build, I cannot accept that the suspension is under stress because of my weight.
At the last servicing, the agent's workshop claimed to have rectified this problem by "skimming" the brake discs, but I continue to hear this squeak.
Are these two problems related and are they something to be concerned about?
The "thud" you heard is most likely from the parking brake. Often, especially with disc-brake systems, the pads tend to stick to the disc after a few days of being idle.
This also happens when the car is parked for a prolonged period in rainy weather. Some corrosion builds up on the disc, creating some resistance.
When you apply a little power, the pads break from the adhesion, resulting in the disconcerting "thud".
All this is normal and in no way detrimental to the car's braking system.
As for the "squeak", try to do the same motion with the parking brake off, but gear lever in P.
You are likely not to hear any sound at all.
In many cars, the suspension design is such that small changes in the ride height - caused by someone getting in the car - require the rear wheels to move rearwards. With the parking brake on, this means the wheel will rotate very slightly against the brakes, giving rise to the sound you hear.