[fsav1126]

Hello,

I’m a newbie to the forum. I’m having an issue with my 2009 DTS. I got in the car (with the ignition off) and pressed the brake pedal. It felt solid and when I turned the ignition on the pedal went to the floor. I changed out the master cylinder as it somehow lost a ton of fluid. Replenish the fluid and did a manual brake bleed of all calipers. Still no solid brake pedal. So then I read about the auto brake bleed feature on some of the obdii scan tools. I bought one and input my vehicles info and started the process. Well barely anything came out of the bleeders and still zero brake pedal. I also got an error message on the scan tool saying that it couldn’t communicate with the vehicle. I’m lost right now and don’t have the money to take it to a dealership to get fixed. Has anyone run into this problem? Any ideas for solutions? Thanks in advance!
Frank

 

[metalrain]

Did you bench bleed the new master cylinder before install?

 

[fsav1126]

I did. I wasn’t sure if air still might be trapped in the abs module?

 

[ac978]

how often do you guys flush the fluid?

 

[fsav1126]

I did a flush about a year and a half ago. Didn’t have any problems with that.

 

[Submariner409]

Most owners don't regularly exchange the brake fluid. Because brake fluid is hygroscopic - it LOVES water - I do it every 5 years in the cars and trucks. You usually won't find a recommendation to that effect in service or owner's manuals, either. My recommendation comes from driving, building, racing and tinkering since December, 1954.

 

[fsav1126]

Thank you Submariner409. It was the first time I actually changed it so it was the stock dirty fluid in there. I’m also wondering if it could be a computer problem as I’m getting other various codes like the O2 sensors showing low voltage.