Edmunds Answers



  • karjunkie 02/19/10 2:53 pm PST

    If you replaced the brake lines and did not crimp off the lines before removing the old lines, you may have quite a lot of air in the system. The only solution is to have someone pump the pedal like crazy with the bleeder valves open while the second person keeps toping off the brake fluid reservoir. Any shop can power flush the system with a special machine that does this much more easily than the old "pump and fill" method.

  • rottiguy76 02/20/10 8:06 am PST

    I agree with the previous answer. It can be a pain to get all the air out. Make sure you start at the right rear and work your way to the left rear, then the right front, and finally the left front. open the bleeder, one at a time, and keep pumping the pedal until you get a relatively solid stream of fluid. Once you have a solid stream move onto the next. Finally, do it all again using the conventional method of three pumps and hold it while your assistant opens the bleeder. If you still dont get a good pedal, it may be necessary to have your local garage or dealer perform a "service bleed" on your ABS system with a scan tool. What this does is manually actuates the hydraulic control unit thus bleeding out any trapped air. Hope this help!!

  • karjunkie 02/20/10 10:45 am PST

    rottiguy76 made an excellent point that I forgot to mention. Always start at the wheel farthest from the brake master cylinder which is the passenger side rear wheel. He is also right about the ABS pump but I think you can get around that by bleeding in the correct fashion.

  • tuberocity 10/28/10 10:14 pm PST

    If I understand you correctly, you replaced the steel lines, and not the brake hoses which connect to the steel lines? If so, you are most certainly looking at going to your local trusted mechanic to have your ABS brakes blead properly as you need a special brake scan tool that opens and closes the various areas of the ABS unit so no air enters as the fluid fills in the areas contaminated by air. No other way to do this, well, there is one way, but I won't go into it here, you can look for it on the net, and it is not always successful, and can actually be dangerous! I think it was on Edmunds, and involves getting your ABS system to lock up the wheels while driving the vehicle. A GM Scanner as far as I know is about $2k on EBAY, but unless you have the money to burn, or plan on doing brake jobs on a normal basis, a $50-$75 bleed job is the better route. Not sure if there is a cheaper scanner out there that will open the GM valves in a GM ABS system, but you can look. I did research myself, and the answers I got were there is no way to get air out of the GM based ABS unit without a scanner. A cheap $89 scanner will read all the brake info you need for repairs, and what parts to buy, but it won't open & close those valves for a propper bleed. Hope this helps someone


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