air bubbles remain after bleeding the brakes

1993 PONTIAC GRAND AM

150,000 MILES • 3.3L • V6 • FWD • AUTOMATIC

93GRANDAMPROBS

MEMBER
3 POSTS

Replace rear brake shoes and wheel cylinders. At that time replace front calipers. Bled the system. When car is not started has a firm brake pedal but when you start the car the pedal goes almost all the way to the floor.Waited a couple of hours and re-bled the brakes. Found more air bubbles. Once all the air bubbles were removed. Had a firm brake pedal without the car being started. Started the car and the brake pedal did the same thing went almost all the way to the floor. Any suggestions on how to get this problem to go away?

Aug 11, 2016 at 1:44 PM

CJ MEDEVAC

✓ASE Certified Mechanic
11,004 POSTS

Have you let the master cylinder run dry?

Do you have your drum brakes manually adjusted outward, close to, but not dragging the drums?

Bleeding technique?

Please see my link below/ and also the link within it. Study the #1 and #2 man part! Disregard anything that does not apply to your vehicle.

https://www.2carpros.com/questions/brakes-59437189

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The Medic

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Aug 11, 2016 at 6:36 PM

93GRANDAMPROBS

MEMBER
3 POSTS

Master cylinder was never ran dry. The bleeding sequence was R-rear, L-rear, R-front, L-front. Rear drums are adjusted correctly. Put the emergency brake on and the car won't roll down the driveway and there's no drag.

Aug 12, 2016 at 8:28 AM

93GRANDAMPROBS

MEMBER
3 POSTS

What I'm not understanding is when the car is not started there is a firm brake pedal but once the car is started the brake pedal drops about 1 inch from the floor. Any information would help greatly.

Aug 12, 2016 at 8:37 AM

HMAC300

✓ASE Certified Mechanic
48,601 POSTS

you can try a power bleeder or it may have to go to a mechanic to get air out of abs unit a lot of times this happens.

Aug 12, 2016 at 1:22 PM

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