Either air in the lines or a stuck piston

 

I should take the wheel off again, and look at it more closely. I was trying to get a job done (oil change, rotate tires) when I noticed it was not grabbing at all, and I didn't follow up at the time. I think it's all mechanical, not involving the hydraulics. If that's true, could be (1) stuck or o/w damaged cable (2) stuck mechanism at the wheel or (3) pads seized.

 

Had an issue on a car with the same setup where the caliper would stick when the parking brake was applied; ended up with 2 basically frozen rear calipers.

I’d get the wheels back up and confirm the brakes themselves are working on that wheel from the pedal first, and then start investigating further.

 

My local mechanic replaced the left caliper. Regular braking is better too so, I figure the entire caliper was stuck. They used an aftermarket caliper, said the oem was stupid expensive. Wonder if I (or someone) could've done something with little $, with a pry bar and hi-temp grease or something. Emery the corrosion out of the piston bore, say..

 

Try inspecting and adjusting the cable. A split in the single to dual cables. One to the left and one to the right. After the split is where your problem is. If the brakes work fine with normal foot braking them it's the parking brake cable system. If not then you have a caliper problem. You need to isolate the problem before throwing parts at it.

 

It was the caliper & not the cable. They guessed it would be the cable & had one on hand, but didn't use it. The regular brake was not working either, I'll guess, since pedal effort was lower after the fix & it seemed to be stopping better. It was the rear brake, so hard to tell in the absence of maximum braking.

 

Glad you got it fixed. 👍