I have a 2005 scion xb, I have replaced brake pads and master cylinder, I've bled and bled the brakes, but foot petal still goes to floor, have nothing leaking either, help

bleed the spliter vale out uderneath car near back

Brake line busted somewhere? Is the linkage to the master cylinder intact? Master cylinder might have been installed incorrectly.

Hello Patricia,

Have you checked the master brake cylinder reservoir for brake fluid loss?

I don't suspect the master cylinder as you have replaced it... but am more suspect of a leaking brake line or fitting which should have
been discovered when you had the system bled.

The only time I ever had a rear brake problem with a 2500 series Chevrolet was due to seized rear brake caliper guide pins...as your calipers are also new that is not your problem.

If your brake pedal feels spongy and travels to the floor board you have air in the system, a brake fluid leak or a failure in the power steering system, such as a broken hose, broken power steering pump drive belt, or failed pump, would result in a loss of pressure to both the hydro-boost and steering.

Find more information here:

. Hydro Boost Power Assist Systems Operation Diagnosis and Repair

fluid is by passing rubbers in master cylinder . replace unit. noise if you are running engine could be air leaking from faulty booster unit

it's a long shot but look under your dash and see if the spring to the brake pedal has come off

have someone who knows what they are doing attempt to bleed it. if it cannot be bled, then you are looking at a new master cylinder.

Hi:
If you have replaced all pads, and see no leaks at any wheel, and have bled your brake system, then most likely your brake master cylinder has failed.

When you fixed the brakes, did you take the lid off the master cylinder. I just wonder if you spilled out your brake fluid. The only reason the pedal should go to the floor is if the brake fluid is gone or the master cylinder is not working. Check the fuse. Check the brake fluid level. The pedal only goes to the floor if there is no back pressure in the lines between the master cylinder the lines to the brake pistion on the calipers. Please give me a good ratin and keep me informed.

pump the pedal about 10 times and see if it comes back up, u need to pump the caliper pistons out after a brake job.

possibly new master cylinder is defective