firehose777

I was due for a brake job so I pulled the wheels off and realized the RT caliper was seized. So I replaced both rotors, calipers, pads and both brake hoses. Bled the calipers like I've done a million times. Made sure the master was full, and took it for a test drive. Pedal just drops to the floor.Pump it a few times, it comes back. After a few seconds, back to the floor again. Repeated the bleeding process again, no air came out. Went thru a qt of fluid. Took it for a drive, right to the floor. I can pump it and it will firm up, but after a few seconds, it's back to the floor. Any ideas?!

vintageman

Had the same exact issue a few months ago on a durango that I was selling. Turned out it was a rusted brake line that ran along the rail to my rear brakes. Are you loosing fluid anywhere on the ground? If you cannot see any leaks but have to keep adding, I would check the master cylinder and see if it is bleeding into the brake booster itself. You have to remove the MC to determine that though.
Good luck, let us know what you find out.
Tom

firehose777

No leaks that I can see anywhere. This didn't start until I replaced the parts I listed in the post.

vintageman

By any chance did you disconnect the brake booster vacuum line, it has a habit of pulling loose on the back of the engine end and brake pedal ends up going to the floor also.

firehose777

No, never did anything under the hood except add brake fluid. It will firm up with a few pumps of the pedal, but goes spongy again within seconds. I'm afraid I might have gotten air into the abs system when I changed the lines. I really don't wanna have to pay a shop to bleed the abs system with a computer. Like I said, they worked fine before I changed everything, and I bled the calipers until I had good fluid flow from the bleeder on each side.

techrep

iTrader: (1)

did you start in the rear first...regardless if you changed the back's

firehose777

Never bled the rears.

grss429

that very well could be the problem

firehose777

Yeah, I guess. I didn't figure air would make it back there when I never touched the rears.

techrep

iTrader: (1)

when bleeding the brake system.. always start the furthest from the master cyclinder and work your way forward.