Tools needed:
10mm Flare-nut wrench
12mm deep socket
10mm socket
Socket extension
10mm open wrench
12mm open/box wrench
Needle Nose pliers
Small-Medium Vice-Grip pliers (I find using them to be easier than standard)
Siphon hose/old turkey baster/vacuum pump
Clean bottle (we do not want to contaminate brake fluid)
Hacksaw/cut-off tools/file - (only if you don't want to deal with the intake manifold tab)
(The following are only needed if you purchased a JDM ITR mc/bb)
Vice if you have one
Pipe bender/bending spring


See the difference in the boosters??


MC Differences


JDM ITR mc (notice the side-mounted hard line is on the opposite side of USDM mc)

USDM Civic mc


Specialty tools

Step 1: Siphon/suck as much fluid from the civic mc as possible.

Step 2: Remove the master cylinders from the boosters (both the ITR and the civic set). Of course this means that you will be disconnecting the hard brake lines from the mc too. While you’re at it, remove the hard line that connects to the side of the mc from the proportional valve as well…some bending will need to take place here (especially if you have a JDM ITR mc, where the side hole is on the opposite side - rhd in Japan)
W/o removing them you cannot get the civic one out of the bay and you certainly couldn't get the ITR one in.

Step 3: Crawl under the dash and remove the cotter pin from the clevis pin behind the brake pedal.
Remove Clevis pin and put it somewhere safe…and somewhere where you won’t forget where it is...

Step 4: While stuck uncomfortably under the dash remove the 4 nuts that hold the civic booster to the firewall.
The 2 on the left are easy to get off, where the top right requires a lot of patience because it’s really hard to get to, and the bottom left nut requires the extension and the deep socket combo in order to reach easily.

Step 5: Crawl out from under the dash and return to the engine bay.
Remove the vacuum hose from the booster (pliers - vice/standard).
Unbolt the hose stays above the booster.
Unbolt the throttle/cruise cable stay
Slide the wires off the stay and unbolt it from the shock tower.
(Tie all things as far away from your work space as possible…anything left behind will only serve to piss you off later when fighting to get the booster in)

Step 6: Pull civic booster from the firewall and fight with it until it is completely removed from the bay. This IS NOT easy w/ an engine still there. Good luck…

Step 7: Time for a break…

Step 8: Get ready for a fight. It’s time to put the ITR booster into its new home. Because you tied off all the wires and cables it shouldn’t be THAT bad. Oh wait…yes it can. The y8 intake manifold (maybe others as well…I’m not positive) has a great little tab that sticks out and serves no purpose.
Now, here is where you can, this is totally optional, cut the intake manifold’s tab off. I removed about 7/8 of the tab to help clear the booster.

If I hadn’t, I am sure I would’ve fought with it MUCH longer. There is nothing to the tab, so cutting it will not have any ill results (if you cut too far…you can always JB weld it up).

Step 9: Continue fighting w/ the booster until you get it to where it belongs. This can take some time depending on your luck…it took me over an hour of straight fighting.
(I disconnected the brake lines from the prop valve to get a little more clearance).
When it does finally go where it’s supposed to, be sure that the clevis pin is aligned correctly so it can connect to the brake pedal. There is no room to fix it once it is fully installed…

Step 10: Once the ITR booster is in place, crawl back under the dash and replace the 4 nuts, clevis and cotter pins.

Step 11: If you bought a JDM ITR mc

its time to take a look at the hard line you removed. See how it’s bent the opposite way of what you need? Take your pipe bender and start to work out the bends, LEAVING THE ONE CLOSEST TO THE MC (90*). This part of the line doesn’t need to be re-bent…we’re just going to flip the rest of the line instead…this also means that our 90* bend is going to turn into a 180* bend (or as close to it as possible). Once is somewhat straight (minus the one 1 bend) stick it in the vice and CAREFULLY tighten it to remove all the little bends in the line that you couldn’t do by hand. This is important to do because all those little bends add up to distance and we need as much as we can get out of this line. Be sure to do all your bends slowly so the line doesn’t kink on you and clamp shut.


Step 12: Now, the 180* bend needs to be as sharp a turn as possible so the line reaches both the mc and the prop valve. Try to put a small bend directly after the flare nut as well to better clear the shock tower. A bending spring works great…but careful people can do it w/ their hands (I did).

Step 13: Once your line is somewhat decent

take it over to the prop valve and install the one end. This really makes it easier to install than trying to do it after everything else is installed and it’s hard to get back there.

Step 14: Install the 2 hard lines to mc and then bolt the mc to the booster. If you have the JDM ITR piece you'll see why the little bend after the flare nut is there. Installing the lines before connecting the mc and bb helps to bend the line a little more before installing it, and thus a better fit (its all custom, so trial and error).

Step 15: Play around w/ the mc and connected lines until you’re able to get the mc onto its bolts on the booster. It may sound dumb to try to fit the mc on AFTER the lines are connected, but its much easier doing it that way than to fight w/ the line after the mc is installed and you have zero room to work with and install the side line.


Step 16: Tighten everything down, replace all the cables, stays, and hoses to their original places, pour in your brake fluid, bleed the brakes, and drive away w/ your new larger mc and booster. Remember to test it out in a neighborhood or back-street first to make sure you installed everything right and you have no air in the brake lines. If you did it all right you will definitely notice a nice difference in pedal-travel distance. :goodjob: