Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi Ray, it's not unusual for you to not get the back part of the master cylinder reservoir filled with fluid. Double check the fluid level first. Fill the reservoir all the way to the brim and then open the rear bleeder and see fluid eventually drips from the bleeder. It may take awhile before it starts dripping. If you don't get any fluid try loosening the master cylinder at the booster and pull it away from the booster then see if it starts dripping. Let me know what happens.
When you let go of the pedal the master cylinder will suck in air if you leave the bleeder open. Only open one bleeder at a time. Start at the right rear. Connect a rubber hose to the bleeder and route it into a clear bottle of brake fluid. Keep the end of the hose submerged in the fluid while a helper slowly pumps the brake pedal. Pump until no more air bubbles come from the hose then have your helper hold the pedal to the floor while you close the bleeder. Repeat the procedure at the other 3 wheels. left rear, right front, left front.
Do you get fluid from all of the other bleeders?
Try going right to the master cylinder and open the lines and see if you get fluid from the master when you push the pedal down. If you don't get fluid try loosening the master from the booster so there is about 1/4" clearance between the master and the booster and try it again.
If the rod in the booster is not letting the cylinder come all the way back it won't draw any fluid from the reservoir.
Not really, sometimes you can screw it in but it is usually a fixed rod. If loosening the master allows fluid to flow to the calipers I suspect that you may have the wrong master cylinder installed.
Sounds good Ray. Have a Happy Thanksgiving.