Brakes not working properly when you press the brake pedal becomes hard and pushes against pressure

Question edited for clarity, wrong type of brake/break.

If you brakes have ABS, you have to bleed the brakes from the caliper up to the master cylinder using a pressure bleeder. It also works better on normal brakes because it pushes the air upwards which is its natural way, air rises in liquid.

_______power brake booster, check vacuum to booster and the check valve for brake booster. primary symtom is high hard pedal that requires greater then normal pedal pressure to stop car. testing booster= pump brakes several times with engine off to deplete stored vacuum. turn on engine with pushing slightly on brake pedal. you should be able to feel the pedal fade away a bit, and then become firm. But not hard. if you feel nothing at the pedal when engine starts. Brake booster is not working. Good-day! make sure vacuum is going to booster with engine running. it may just be a bad vacuum line or check valve.

Hi P, The most usual cause of the brake pedal action becoming hard is a defective return seal in the brake master cylinder. When the brakes are depressed fluid is pushed into the wheel cylinders, activating the brake pads and shoes. After a few operations of the braking system the fluid fails to return to the master cylinder and with each further action the brakes become tighter. After the vehicle stands for some time the pressure gradually releases and frees the brakes. Have the brake master cylinder checked. It's good policy to replace the brake fluid once or twice a year as part of the major service. Regards John

Hi, when the brake pedal is hard check the pipe from your booster to inlet manifold. Or from the rear of your alternator to the brake booster.

The brake master cylinder is the device that supplies hydraulic pressure to the brakes when you press the brake pedal. It is located on the drivers side of the vehicle under the hood back by the firewall. It is under the brake fluid reservoir. Let me know if you have any questions and I'll do my best to answer them. Thank you for using FixYa.com!

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The air seeping is a dead giveaway. Your power brakes are now manual brakes, but stiffer. The diaphram in the brake booster has torn and the hissing noise is the engine vacuum escaping (you hear it louder when you depress the pedal right?). Replace the booster and you will be fine. The brake lights probably don't work because you can't push the pedal down far enought to release the switch. Please rate. Thanks.

the booster is the problem, or a hole or leak in vacuum line to booster check the check valve also ! from manifold. heres the symtoms of a bad brake booster. primary symtom is a hard pedal on application, to test booster. pump brakes several times with engine off. to deplete stored vacuum. turn on engine with pushing slightly on brake pedal. you should feel the pedal fade away abit and then become firm. but not hard. if you feel nothing at pedal when engine starts, brake booster is not working! check the vacuum lines first!!

Check the caliper sliders, they may be seized causing limited brake pad contact. Also check the calipers for siezed pistons.
After bleeding the system, sometimes the proportioning valve will have to be reset manually. You can do this by having an assistant press the brake pedal and open a bleeder screw slightly on one side [ front or rear ] of the system, it may reset. If not, try doing the other side of the system.
If the brake pedal seems to be pushing back against you then either the Brake Booster isn't getting proper vacumn, or is faulty.
If the vehicle has drum rear brakes, make sure they are adjusted properly. If they are set too loose the pedal will feel spongy and low.
Hope this helps.

hi from uk you do not say if engine is petrol/diesel ? reason for asking is that on petrol engine the vacuum for b/servo is from inlet manifold whereas on diesel it is created by a seperate vacuum pump usually on uk models by being bolted/driven on the alternator by belt ? however from what symptoms you describe i would suspect that on 1st application on brake pedal ? the vacuum is gone hence pedal goes hard due to loss of vac assistance ? whereas vac should last for 2 or 3 applications ?b4 all vac is gone when vehicle/engine is off so the problem may be the vacuum hose to servo unit is leaking or split ? or the servo inner piston diagphram is leaking as you press pedal resulting in no assistance unfortunately servo is not serviceable and req's replacement this is not beyond diy if you wish to? on diesel vacuum is from pump but same principle as to vacuum for servo this may be pump thet is worn out ? or hose split ? or on some occasions thedrive belt slack? also on some diesels the vac pump can be driven off therear of camshaft ? in which case pump considering age of car +milage ? may be pump fault SO hope you understand all above? try this run engine then stop press b/pedal and if pedal goes hard or slowly pushes back ? this is vacuum being used and leaking you can test pump with vacuum guage then check if operating and holding good vacuum if not pump is worn if yes then may well be servo diagphram you can buy servo units without the b/master cyl which you will not require

check that the master cylinder is not locking on with a pressure build up the cyl may need replacing probly does