Why does steering wheel shake when brakes are applied on my 'o7 chevy HHR?

They are right. If you had steering wobble while driving along, it would most likely be a missing wheel weight or warped wheel. If it is an off road vehicle, possibly even a clump of mud stuck on the inside of the wheel. IF, however it only occurs when you brake, it is down to a warped brake disc. Imagine looking at a plate edge on. The plate is warped. If it is out of true by 3 mm, when you spin it it just wobbles a bit but if you couldn't see it you would never know. Now imagine it spinning but this time you gently pinch it between your thumb and fore finer. Now you can feel it wobbling. Now imagine the plate is your brake disc, and your finger and thumb are the two sides of the brake calliper. As you put your foot on the brake, the two brake pads grip the warped disc and transmit the wobble back up the steering column to the wheel and you. That's why the dealership can tell without looking at the car that your wheel wobble when braking, is the brake disc. Some cars are prone to warped discs. Sometimes it can be caused by 'sporty driving' and heavy braking. They warp due to heat build up. It may be worth looking at a set of upgraded discs. Maybe a set that are drilled or grooved. The holes and grooves help to dissipate the heat and prevent warping. Plus they help remove brake dust from between the pad and the disc to improve braking. That's why racing cars use them.

It' an educated assumption, the front brakes are alternately grabbing and pulling to their respective sides,thus the steering wheel jerks r then l in rapid succession.I however would take it to a brake shop,dealerships r very expensive.

It sounds like brakes to me. I don't think an alignment problem would make it shake. Get a second opinion if you're worried, and a second price quote. Dealerships are almost always higher in price, but they usually guarantee their work.

each so often once you place new pads and rotors they could be good broken in because of the fact if no longer the rotors and pads will set in uneven inflicting vibrations and noise. look on the brakes and rotors for warping if there is uneven sense to the outdoors of them then thats your challenge. Get new brakes and pads and have them good broken in and your challenge could circulate away. Oh torn balljoints is a undesirable factor very risky in case you have been to coach tense sometime they might truthfully snap and your automobile will lose steerage, balljoints are the only component to the suspension connecting to the administration hands so theres no thank you to regulate your vehicles whilst they snap. substitute them there undemanding, and reletivly low-priced in case you do them your self i say approximately 25-fifty 5 a chew. if your no longer routinely improve even though it somewhat is beneficial to hunt for a expert! please restoration them asap, avert a damaging twist of destiny.

sound slike brake rotors are warped. Make sure if you get them replaced, they torque all the lugs equally or else you will have the same problem down the road :( usually if it needs alignment it shows tire wear or else it would do it w/ or w/o brakes applied

They aren't messing with you. It's the brakes. Putting this off will not only do additional damage to your car, but it's also going to put you in a really dangerous vehicle.

the disks are warped so when you try to hit the brakes the brake hits one spot on the disk but not the rest of it so its like hitting and releasing the brake very fast

definitly rotors.... most common problem in HHRs and cobalts