2000 GP GT soft brake pedal

[aliasmax]

Hi all, I have a 2000 Grand Prix 3.8 with 65,000 miles. Bought the car new for the wife to drive. The front brake lines rusted out. My wife has a friend who is a backyard mechanic. She had him replace the front brake lines, from the abs block to each front wheel. Well she finally told me that the brake pedal is not right. I went out and sure enough with pressure on the pedal it goes to an inch off the floor. I bled all for lines at each caliper, no change in pedal. I bled almost a full bottle of fluid. You can pump the pedal for 10 minutes and no change in the pedal. I don't think it is air in the line. I changed the pads and rotors on all four corners last fall. The brake pedal was normal then. What do you suggest I look at now? thank you.

[Tech II]

Sounds like there is still air in the system.....it's possible there is air in the ABS system......may need a scan tool for this to get rid of the air....

[aliasmax]

Originally Posted by Tech II

Sounds like there is still air in the system.....it's possible there is air in the ABS system......may need a scan tool for this to get rid of the air....

How do I get the air out of the abs block if that is the problem. What will a scan do? I don't have a light on? thanks for the reply

[gmtech1]

Originally Posted by aliasmax

How do I get the air out of the abs block if that is the problem. What will a scan do? I don't have a light on? thanks for the reply

A capable scan tool has the ability to command the BPMV ( ABS block) to cycle the internal valves and purge out any trapped air. Some will also let you run the pump motor to push fluid to each caliper. If you have a dirt/gravel road nearby, you can take the car out and do some ABS stops. this will also cycle the valves. Be sure to use some common sense when doing this (No other cars around, no chance of hitting anything or anyone, no ditches, elephants, land mines, ect...you get the idea). Then bleed the brakes again. I have had some success with this process.

[aliasmax]

Originally Posted by gmtech1

A capable scan tool has the ability to command the BPMV ( ABS block) to cycle the internal valves and purge out any trapped air. Some will also let you run the pump motor to push fluid to each caliper. If you have a dirt/gravel road nearby, you can take the car out and do some ABS stops. this will also cycle the valves. Be sure to use some common sense when doing this (No other cars around, no chance of hitting anything or anyone, no ditches, elephants, land mines, ect...you get the idea). Then bleed the brakes again. I have had some success with this process.

I will try the dirt road trick for the ABS. thank you for the info.

[aliasmax]

The road trick did not work. Took it out slammed on the brakes a few times, took it home and bled 1/2 a bottle of brake fluid out of the front two calipers and no change in pedal. Still goes to within 1 inch of floor.