Question about 1998 GMC Sierra

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I lost my brakes on my 98 gmc sierra 1500. I replaced the booster and the Master, but can't get all the air out of the lines. The brake pedal remains mushy and goes all the way to the floor. Is there a vaccuum line that could possibly have a hole in it thereby causing air in the line or should i be looking somewhere else?

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  • GMC Master
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Just keep bleeding the brakes the air will come out. If you have two people one on the brake pedal and one at the brakes have the person at the pedal push the pedal and hold it, the person at the brakes opens the line then closes it with the other person still pushing. once it is closed theperson relieves the pedal. do this 3 to 4 times then check the fluid level and fill. do this to every wheel starting with the wheel furthest from the master cylinder and working your way closer. Also some thing to check is if you have drums in back is the adjustment of the brakes. If they are not adjusted properly you will not get the full pedal. they should be adjusted out close to the drum but not rubbing. also beware of the lip on the drum. it will throw you off. if you can take a grinder and grind off this lip. The method i just explained pushes fluid thru faster. I have had to do this a couple of times on some vehicles.
Good luck
Randy

Posted on Nov 10, 2010

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