I've had issues with the front end of my car shaking while braking on my 2000 Camaro SS since about May/June of 2014. You can feel the shaking in the steering wheel but not the brake pedal especially at higher speeds. I put so few miles on it that I just ignored it at first (5 Miles a day round trip). It's my daily driver and I have 4 kids so I just couldn't find the time and money to do anything about it. In December I decided I'd had enough and I took it to a shop. They told me the shaking could be caused by the fact that the outer tie rod ends were destroyed. They replaced the outer tie rod ends and did an alignment. While the car drove better the issue was not resolved. I couldn't afford to spend anymore at the time so I just let it go. Over the weekend I replaced the front brake pads and rotors with Duralast Gold parts hoping to resolve the issue but unfortunately the issue is still there.

Where should I look next? I haven't done anything with the rear brakes so it could be something there I guess even though its the front end that shakes. I've been told it might be a proportioning valve but after some research I couldn't really find a replacement valve that wasn't after market. Not sure if I should focus more on the brake system (Booster, Master Cylinder) or the Suspension.

I know it's difficult to troubleshoot over the internet but any help would be appreciated.

 

Maybe try getting a picture of anything you think could be an issue up and the techs on here may be able to do more with that.

The shop you mentioned replaced the outer tie rods did they check the inner ones? If they say the outer ones in bad shape could cause that I would assume bad inner ones could do the same...maybe.

 

Just when hitting the brakes you're next spot to look at is the calipers and hoses. A wheel bearing can also be causing this but usually they howl first.

 

inner tie rod ends rarely go bad. i would look at wheel bearings/hubs first. then look to the bushings on the upper and lower control arms.

 

Other things to look for:
1) Bent wheel
2) Bent bearing hub
3) Rust chunks between the hub and rotor causing rotor to have a wobble
4) Slop in the steering rack
5) Wear on other steering components
Shop should have checked for/caught all or most of these. That doesn't mean they did though.

 

#3 is a very common problem. Not cleaning the hub bearing enough and installing new rotors can cause the same brake wobble as bad rotors. Every time I have seen "new rotor still shaking when braking" on a work order it ends up being that. Most of the time when the is loose suspension parts the is a car wanders or pulls added on the work order.

 

Whenever I do a brake job, I take a sharp chisel, to use as a scraper, and clean the mating surfaces of the axle hub, rotor (if old one is still good), and the wheel. I scrape till I see bare metal, and always get some sort of chunks or corrosion buildup coming off.
I highly doubt that repair shops bent on getting you out of there asap are going to be nearly as meticulous. "Good enough" isn't always good enough.

 

I have a scotch pad that is designed to go around the studs and I use it with angle die grinder. With that setup I can clean a hub bearing in about 30 seconds. I think most full time mechanic in the rust belt areas do this because vibration on a recent brake job would be a come back and they may be fixing it for free.

According to GM over torque and uneven torque (AKA using a impact) is the biggest killer of rotors but I think that takes a little time and a few heat up before it will warp the rotor.

 

could be the steering rack like said there is either 6 or 8 bolts that loosen up over time ,does the car wonder sometimes ,mine has done it for like long time an is do to be fixed up wonder ,I never break very hard with these cars use the tranny to slow down ,it could be combo of everything ,though you replaced alot ,clean up the calipers an paint them .slows rusting down ,I had mine sand blasted then painted not rust,saying not the brake pedal makes me think those bolts get loose on most all I was told bye gm mech ,its mostly labor couse there behind the firwall ,under the dash

 

I have the same issue i just stopped driving the car until i can get new rotor's and pads mine are rusted up i think ther PO got the too hot and warped them but i have the same exact problem.

I have came to a conclusion if you spend too much effort trying to find a problem its usually the easiest thing to fix just my FYI