Hello, I just replaced all the rubber lines and hard steel lines on my 02 Tahoe.pedal hard and won't sink down when not running.start it up no petal right to floor.ran a full bottle of fluid thru the system and no bubbles when bleeding . Any ideas ? Master cylinder? Changed out dirty reservoir .before adding fluid.

 

year? make model please

 

Take the m/cyl.off and bench bleed it first. You gotta have the bleeder tubes(they come with a m/cyl) maybe you can buy them seperate. It's two(2) fittings that screw in the m/cyl with short rubber hoses long enough to reach the bottom of the fluid resevoir. Put the m/cyl. in a vise, fill the reservoir not alway to the top, use a large punch etc and holding the lines below the fluid start pumping. You will get no bubbles when it's time to stop. Reinstall m/cyl and bleed the r/r first, then l/r, r/frt, then l/frt. Only push brake pedal half way down when bleeding, or you will trip the diverter valve. Good luck.
David g.

 

also, If the system has a proportioning valve; a special tool is required to release the valve for bleeding the rear brakes. when you develop a fairly firm pedal...have a shop perform an automated system bleed with a scan tool.





the trick when replacing brake lines and flex lines is to never let the m/c empty. slightly depressing and holding the brake pedal with a pry bar will close off the ports in the m/c so fluid will not drain.