Bleeding brakes on a 1998 silhouette

That sounds more like a major leak or a bad master cylinder can you pump the brakes up to a hard pedal with the vehicle off?

Still air in system, sounds like the master cylinder has ran dry during the bleeding process, pumping more air into system. The lines running to the rear brakes are long, so you must bleed the fluid out the bleed screw in the rear 10+ times each side. Bleed, bleed, and bleed some more, keep bleeding untill that pedal feels good.

first check on every wheel make sure you see no wet . from brake cyclinders leaking. make sure brake fluid is full. when you replaced master cyc. did you bleed that before you hooked lines to it if not do that. abd bleed all brakes again. if still pedal goes down then it is the brake booster its self. hope this helps.

Sounds to me like the master cylinder needs to be bleed.Master cylinder has to be bench bleed before installion

yes may need to bleed lines at master cylnder

You may need to further bleed the brakes. Something pumping to bleed the brakes can **** in air at the brake fluid reservoir. Try using a vacuum pump to **** out brake fluid from the release screw at the brake side. Make sure you always have enough fluid at the reservoir.

For left hand drive vehicles: (If the car does not have ABS system you do not need any diagnostic equipment!)

IMPORTANT NOTE: You need using diagnostic equipment connected to the data link connector of the car in order to bleed the ABS block. Follow instructions by scantool equipment for bleeding the ABS block.

1. This bleeding procedure requires two people. Remove the brake system reservoir cap, and fill up with new brake fluid until "MAX" level is reached.
2. Lift the car, or use a channel for access under vehicle.
3. Put the gearbox in "N" - Neutral position, or in "P" - Parking position for automatic transmission.
4. Start the engine and push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor.
5. Begin with the rear right wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
6. Repeat steps no.#4 and no.#5 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

7. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
8. Continue with the rear left wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
9. Repeat steps no.#7 and no.#8 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

10. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
11. Continue with the front right wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
12. Repeat steps no.#10 and no.#11 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.

IMPORTANT NOTE: All the time check the brake fluid level in the brake system reservoir, and fill up if necessary!

13. Push the brake pedal firmly for 4 - 5 times to the floor, and maintain the brake pedal pushed to the floor, engine idling.
14. Continue with the front left wheel. Another person remove the dust cap and loose the brake caliper bleeding screw until the brake pedal goes to the floor. At this moment maintain the brake pedal pushed to the floor, engine idling, and tight the brake caliper bleeding screw. Use a plastic hose: one end connected to the brake caliper bleeding screw, and another end inside a recovery bottle for used brake fluid.
15. Repeat steps no.#13 and no.#14 until no air flows through the brake caliper bleeding screw. Tight the brake caliper bleeding screw, and put the dust cap in their place.
16. Now the brakes are bleeded. Check the brake fluid level in the reservoir. Fill up with new brake fluid until "MAX" level is reached. Put back the brake reservoir cap.
17. Test the car brake system. The brake pedal movement no more than 1/3 of total stroke until the floor, when brake pedal is applied. Maximum admissible is 1/2 of total stroke.

WEll, solve the pedal to the floor and the air noise will be okay.

Check all 4 wheels brakes, and all lines for leaks, if okay replace master cylinder, be sure to pre bleed it.

Step1
If you had a brake job you might have air in the system that needs bleed out.
Crack open the bleeder on the caliper and watch the brake fuild come out steadly and close it and don't pump the pedal. Do this to each side this is called bench bleeding and watch the brake fulid level while you are doing this add fuild as you bleed each side.


Step2
Also sounds like a leaking line check under the car for a leaking brake line. Next would be a master cylinder problem. But more than likely a brake line might be rusted up and leaking, sooner or later you will not be able to stop. If its a leaking line it will leak all the fuild out of the master cylinder. You can replace the line and use the bleeding procedure in step one.

sounds like a bad diaphragm in your brake booster. listen for air while running at booster , disconnect vacuum hose depress pedal if it is good there should be a big difference in pedal