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Discussion Starter · #1 · (Edited)
I have been keeping up with my Cobalt over the past two years. Runs great. Has had great fuel mileage. But as of recently, the last two months or so, mpg has gone down. I thought maybe since I’ve been using it more in town rather than taking highway trips was just it.

But as I’ve been working to take care of some front end vibration I had been setting the car up to put it on the lift at the shop. I noticed the car wasn’t so easy to push forward. Thought maybe I left it in park, but it was actually in neutral. I found the front right wheel was kind of hard to turn. Inspecting the brake rotor, it had no bluing from overheating. The wheel freed up pretty easily. So I had a look at the caliper pins and tried re-greasing them. I had greased them the last pad change over a year ago. They stuck again after reinstalling. I figured it was the pin that has the rubber isolator on the end of it. Sure enough the rubber had swollen up and was binding inside the caliper bracket. I removed the rubber and it’s fine now. I will need new caliper pins though. They’re usually $10-$15 so a cheap fix.

I see a lot of issues with calipers sticking and causing lots of different things to happen. Pulling problems are common while braking. Overheating brakes are also common. I don’t really have too many people notice performance issues like poor acceleration or loss of mpgs. Although I may notice that while test driving a car for other reasons.

Anyways the Cobalts mpgs had started to average 19-21 mpg which is strange. Now that the brakes aren’t sticking it’s back to the regular 24-27 mpg in town.

Also brakes that are sticking are really not great on the transmission either. Can be compared to having the car loaded down or towing something. I should have noticed something was up earlier. I’m probably lucky the brakes weren’t ruined. I’m sure they would have been if it had gone on much longer. It must have started getting pretty bad the past week or over the weekend though. I know I had rolled the car forward by hand a couple of weeks ago in the garage when I was cleaning it and it had no issue doing so.
 

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Discussion Starter · #2 ·
The brake hoses were the major cause of the fuel mileage dropping. The issue became worse and replacing the hoses seems to have resolved the problem.

I’m not sure how people don’t notice brake problems like this. I have seen customer come in with the same thing happen but don’t usually mention the fuel mileage being bad.

In my case I thought I had the problem fixed. But it got worse a few days later. Finally got to where from a stop the brakes would stay holding after releasing the brake pedal. Mileage really went down as this problem worsened.
 

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So how did you discover collapsed brake hose? Just guessed and replaced them and the problem appeared to go away?
 

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Discussion Starter · #4 ·
Well it seems like the symptoms are mainly the same on most any vehicle. Or very similar. The sticking as I’ll say, would come and go. Wheels would be easy to spin if the car was parked. I could drive a few miles, and finally when it got bad it was maybe five to seven stops and it was really causing the brakes to overheat. This time I could smell the pads getting baked. The hoses are also the least expensive and easiest to replace. Other than that, the caliper pistons themselves were able to be moved by hand. When they have issues, they may be very difficult to compress in, even with the compressor tool I have. The caliper slide pins were ok after I greased them and put new rubber end pieces on. So basically a process of elimination from inspection the calipers, slide pins, and then hoses. I was also worried the master cylinder may be a problem. Although I haven’t really ever seen one cause sticking brakes.

I however am considering replacing the calipers now. They are ok but I know they got awfully hot. Also original to the car. Plus they are likely contaminated with debris from the interior of the hoses. They at this point are working fine though. They are only $42 each locally so probably worth it to just replace.
 
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