Download From - http://ps3jailbreakteam.free.bg/

How To: Jailbreak PS3 on 4.00 only

STEP 1: Plug a USB stick into your computer
STEP 2: Create a folder in the root of the USB stick called PS3
STEP 3: Create a folder inside the PS3 folder called UPDATE
STEP 4: Download PS3 Jailbreak 4.00 by codeman
STEP 5: Run Downloader and start downloading PS3UPDAT.PUP file which will be downloaded on your desktop
STEP 6: Move PS3UPDAT.PUP to the directory UPDATE that you just created on the USB stick
STEP 7: Plug the USB stick into your PS3
STEP 8: Navigate to Settings Tab
STEP 9: Choose System Update
STEP 10: Choose Update via Storage Media
STEP 11: It will say it found Version 4.00-jb
STEP 12: Choose OK
STEP 13: Accept Conditions and Install Update
STEP 14: After less than a minute, your PS3 will update, beep 4 times then shut down.
STEP 15: Power up your PS3 (You will have to do it on the console and not by the controller)
STEP 16: Your PS3 is now jailbroken!