Left side brake will not release

The described braking concern is symptomatic of contamination in the brake fluid. When oil comes in contact with the O rings/seals in the hydraulic brake system, the neoprene material will swell up and restrict movement of the brake caliper pistons. The caliper pistons will move out against the disc brake pads, but due to the distorted O ring seal, it will not retract while the brake pedal is released. Sometimes, the service person at the oil change station will by mistake put power steering fluid in the master cylinder reservoir and create the symptom. If you find this to be the case, the entire hydraulics system will have to be flushed or replaced and all of the neoprene (rubber) components will have to be replaced. If you do all the underhood service on your car, then you don't have to look very far to discover who put power steering fluid in the brake cylinder

if the caliper is ok it sounds like the flexiable hose is restrcted by the metal crimps on the hose corroded and crushing the reinforced rubber hose restricting the fluid returning back in to the system. change the hose

sounds like caliper is frozen. Can you push the Piston into the caliper when bleeder is open?

The only way to disable a rear brake caliper that is seized is to get a small pry bar and use force to slide it back to the release position.place the pry bar in. The open space top of the caliper
Then if I were in this situation since you come this far I would simply replace the caliper the slide bolts are 7mm Allen type.
then remove the brake fluid feed line don't forget to replace the
copper seals on the main brake fluid feed connector.
then bleed the system do this by opening the air bleed
valve its 8 or 10 mm just crack it open maybe you one full
turn then place your finger on the top were the fluid comes out.
have some one pump brakes slowly all the way down and release
brake pedal continue this until you feel pressure at tip of your
finger then release brake pedal on the last pump hold brake pedal
down and tighten then release pedal.
Good to you!

pistons are sticking in the caliper, plain and simple.. sorry to say its time for replacement of the caliper, if not the brake will heat up and prematurely fail or cause you to skid out of control in less than ideal conditions..it is now a safety issue..please replace it..good luck..on rare occaisions if you can take the caliper back off and work the pedal until the pistons fall out, clean them with a wire brush to remove all the built up gunk on the back of them then open the bleeder screw and reinsert each piston and set in place with a c clamp being careful not to mes up the seals..try that also be sure all air is out of the system..good luck again..

The brake hose is clogged. When under pressure from applying breaks, the piston is forced tight to the rotor. When released the fluid will not return through the hose because there is no real pressure. Replace the hose.
murf427

caliper may be sticking this will require over haul (new seals maybe pistons) do both calipers as a pair or you may find brakes will drag to the right if you only do left side I've found this out the hard way

Good chance of caliper to piston issues like you describe, the pistons must move freely (freely a relative term). Easiest to replace with rebuilt calipers. You need perfect brakes. Consider replacing rubber lines at the same time, pretty easy during caliper job and DO NOT let M/C run low on fluid during this process.

since your complain is on the driver side sticking brake, so i do not suspect that the failure in on your hydrovac, it could be the that your driver side brake caliper piston needs seal kit replacement thats why when you press the brake and when you depress it the piston doesnt retracts. you need to remove the driver side wheel and remove the brake caliper assembly, take off the brake pads, press the brake till the piston comes out, inspect the piston condition and change it if damage along with the seal kit. make sure to bleed the brake before driving the car to release presence of air in your brake system.

you will need to replace the wheel cylinders. always replace both sides and the shoes will need to be replaced also on both sides due to brake fluid contamination. make sure you have the drums resurfaced also!! hope this helps you!