'93 Lumina brake problem

[kwald]

One of the brake lines on my mother-in-law's Lumina corroded and burst leaving her without brakes. The car sat like this for a week or so before I had a chance to look at it (and determine it was a leaking line), and subsequently, the reservoir ran dry.

I've replaced both lines to the rear of the car (the other was corroded the same way in the same place), as well as the rear calipers, rotors and pads. One of the calipers had been leaking and was missing the outer pad. No, I've never worked on her car's brakes before.

Anyway, I've bled the brakes, but the pedal still goes to the floor when the motor's running. I'm guessing this is becuase the reservoir ran dry, but I'm not sure what to do next.


Thanks in advance.

[jeffcoslacker]

Tou are probably having trouble getting the lines primed, and sequence makes a difference also. Here's the scoop:

1. Fill the master cylinder reservoir with brake fluid and keep the reservoir at least half full during the bleeding operation.
2. If the master cylinder has air in the bore, it must be removed before bleeding the calipers. Bleed the master cylinder as follows.
   1. Disconnect the forward brake pipe at the master cylinder.
   2. Fill the reservoir until fluid begins to flow from the forward pipe connector port.
   3. Reconnect the forward brake pipe and tighten.
   4. Depress the brake pedal slowly one time and hold. Loosen the forward brake pipe and purge the air from the bore. Tighten the brake pipe, wait 15 seconds and repeat until all air is removed.
   5. When the air is removed from the forward brake pipe, repeat the same procedures for the rear brake pipe.
3. Bleed the calipers in the following order, (right front, right rear, left rear, left front).
4. Install a box end wrench over the bleeder valve and connect a clear tube onto the valve. Place the other end of the tube into a container of new brake fluid. The end of the tube must be submerged in brake fluid.
5. Depress the brake pedal slowly one time and hold. Loosen the bleeder valve to purge the air from the caliper. Close the valve and release the pedal. Repeat the procedure until all air is removed from the brake fluid.
6. Do NOT pump the brake pedal rapidly; this causes the air to churn and make bleeding difficult.
7. After the calipers have been bled, check the brake pedal for sponginess and the BRAKE warning lamp for low fluid level.
8. Repeat the bleeding operation if a spongy pedal is felt.
9. Fill the reservoir to the MAX line.

[jeffcoslacker]

If you are doing a two-man bleed, obviously you don't have to worry about the last few instructions...but make sure you open the bleeders quickly, and BEFORE the pedal pusher bottoms out the pedal. Make sure they aren't stabbing the pedal into the floor, that can damage the master cyl.

Sometimes if all else fails, open all the bleeders and just keep filling the reservoir until fluid comes out all of them, then pressure bleed one at a time. This gets the lines full and most of the air out. Have to make sure you don't run the master low on fluid, or you'll be back to square one...