yes
If you're only changing the pads, no. You only need to bleed if the hydraulic system was opened or if you wish to flush/change the brake fluid.
Check the brake fluid...
If you have not opened the brake system ie. taken off any lines or lost any fluid, you should not have to bleed a brake system. Brake jobs are best done by experienced technicians.
no
bleed the brakes. check fluid level
Luid You can open the cap on the fluid container when you compress the calipers back it will force the fluid back and then you bleed them to remove any air in the lines.
You can find information on changing your brake fluid yourself is to go online and look up under the information for changing brake fluid. You can also speak with a mechanic.
If you replace any brake component that breaks the brake fluid seal or you let it get very low of brake fluid, yes, you must bleed the brakes.
Good time to replace all the brake fluid. Remove the brake lines from the Master Cylinder and pump the master cylinder dry. Add fresh brake fluid from an unopened can and bleed the master cylinder. Reinstall the brake lines and then bleed all brake lines until you see clean fluid. Keep adding fluid to the Master Cylinder until you are done.Good time to replace all the brake fluid. Remove the brake lines from the Master Cylinder and pump the master cylinder dry. Add fresh brake fluid from an unopened can and bleed the master cylinder. Reinstall the brake lines and then bleed all brake lines until you see clean fluid. Keep adding fluid to the Master Cylinder until you are done.
You have your car towed to a repair station where they will bleed the brake fluid and grease out of the brake system, and replace them with good, clean brake fluid.
no
There may be air in the brake system. Bleed the brakes and see if this helps. Bleeding the brakes requires two people, a quantity of new brake fluid, and wrench the correct size to open bleed valves on brake plates. The brake plate is the flat plate that the brake mechanisim is mounted on, and has a hose coming to it from the body of the car. The hose carries the pressure from the master cylinder to the individual wheel cylinders, and where it connects to the brake plate there is usually a bleed valve, which is a hexagonal piece of metal with a hole in it. When the bleed valve is loosened, it allows brake fluid to drain from the system. If no one is in the car with their foot pushing the brake pedal to the floor, air will enter the brake system through the bleed valve. So, have someone in the car who can push the brake pedal down, open the hood, and remove the cover from the brake fluid reservoir on top of the master cylinder. Have the brake pedal pushed down slowly (to keep the brake fluid from splashing all over the place. Be careful, brake fluid is highly corrosive!) as the bleed valve is opened, and held down until the bleed valve is closed. Repeat this procedeure three times, and then check the fluid level in the reservoir. Add fluid if necessary and go to the next wheel, which should be the left rear, as you want to start with the right rear, seeing as it is the furthest from the master cylinder. Work the right front after the left rear, and the left front last.