after my local brake shop changed the front rotors and brake bads on my 99 grand cherokee the brake pedal is spongy and long, almost reaching the floor. They dont know why. apparently they had a problem with fitting the new pads. I took it to the jeep dealer and they told me the master brake cylinder was leaking and needed to be replaced. many hundreds of dollars later the brakes are still spongy and long and does not correct with repeated pumping. The dealer was also stumped and I complained that nothing changed witht the new master cylinder. what might be the problem?

It could be the rubber hoses leading to the calipers are expanding or the system needs to be re-bled.

I strongly suspect that the jeep dealer didn’t bleed the brakes correctly.

This is what needs to be used.

The old school two man brake bleeding method isn’t nearly as effective as using this tool with the proper adapter.

I also strongly suspect that the local shop had a problem retracting the pistons in order to clear the new, thicker brake pads. They probably cracked a brake bleeder/hose/line in order to retract that piston easier. Thus, introducing air into the system.

Do you have ABS? They may have damaged the ABS when they retracted the caliper pistons.

Could be a caliper with a stuck slider.