I just did the brake shoes on the back of my 2011 LT HHR. Hadn’t done rear drums in 30 years so I decided to watch a few YouTube videos. I noticed that there seems to be two different designs

Mine has a total of six springs holding everything together. The other design only uses four springs.

What years had the four springs and which had the six springs?

 

2006 thru early 2009 had the horseshoe spring style, 2009 thru 2011 had the old Chevy pin thru the spring and a clip to hold the shoe in place, like in your photos

 

Thanks

 

I found a photo of the 2006 style


See the horseshoe spring

 

So. For us southerners, what is up with that corrosion ? Salt ? Leaking wheel cylinder ? Never seen anything like that before.

 

Salt brine!

 

I have.....On the Titanic.

 

Standard rust up here where the water freezes in the winter months. They throw salt and calcium chloride on the roads to melt the ice, sometimes it works! also helps to lighten up the cars for better MPG and keeps old cars off the roads.
fluid in the picture is probably penetrating oil to get the drum off.

 

And lots of break cleaner. HHR came from upstate New York where they use salt instead of asphalt.

 

The winter road salt up here is horrifying. They overdo it. Calcium chloride is the worst. It’s much more corrosive, and it absorbs water from the atmosphere, so it never dries, and because chemical reactions speed up with heat, the rusting on your underbody might even accelerate in the Summer. It EXTREMELY important to flush the cars’s underbody. I do it with every break in the Winter weather, and 2-3 times in the Spring once the salting is over. There are a couple car washes here with the underbody feature, and I made a tool to get under there from PVC pipe with a lot of hole drilled and a fitting to attach to my garden hose.