shaking front end when braking but not all the time
 

i have a 2010 hhr which i love but when braking moderatly , the driver side front end shakes violently sterring encluded, but oddly enough if i just turn sterring wheel slightly either way it stops immediately. I have changed rotor 4 times, pads 2, bearing, lower control arm, caliper, complete strut assembly and connecting link. to no avail. also new tires and alignment. iam ready to give up . any ideas.

Steering linkage??? my best guess

When, if ever, have the rear brakes been serviced and adjusted?

HHR's are somewhat notorious for a problem called "Brake Judder", this occurs when the rear brakes fail to self adjust. This eventually causes your rear brakes to become ineffective, which transfers all of the braking effort to the front brakes, leading to premature failure, juddering, and other complaints.

Here's a "How To" on adjusting the rear brakes which should be done every 5,000 miles, or at every oil change.

https://www.chevyhhr.net/forums/brakes-%7C-suspension-%7C-shocks-%7C-struts-24/proper-rear-drum-brake-adjustment-procedure-36754/

Possibly tie rod ends? But probably rotors, due to not adjusting the rears regularly.

How offen do the rear brakes need to be adjusted?

Look up two postings above yours in this thread. :)

Just headed out to the garage to adjust the rear brakes on my 07 HHR LT, I did have this iss awhile ago, the outer tie rod was the issue for that time, but in general the rear brakes I adjust every time I rotate the tires 5,000 Klms or 3,000 miles, a bit if overkill to some but piece of mind and no brake judder for me.

The new style self-adjusters on my 2011 seem to actually work once they were adjusted correctly by hand. I think they changed in 2010, maybe 2009.

A couple of experiences with brake shake, (1) stabilizer links were bad or broken, and (2) the struts and strut bearings needed to be replaced. I have experienced brake fading under wet conditions to the point that the next rotors will be cross-drilled. My car has the Brembo brakes on the front. Just wanted to share.

Fade in wet conditions? You'd think the water would cool the rotors not add heat.

Are you road racing? Brembo in the front disc or drum in the rear?

Brake fade is just not something I've heard of on this forum.

Most people say that drilled rotors only look good with no performance advantage. I don't make any judgement 'cause I'm old and feeble, I just drive for a living not for fun.