GrimmSpeed Master Cylinder Brace Installation Walkthrough

The information below is provided as an initial guide to installing the GrimmSpeed Master Cylinder Brace (MCB) in a 2005-2007 Non-VDC Subaru Legacy. It may contain omissions in written content, but these are further explained in more detail in the pictures themselves. Start-to-finish, this is realistically a one-hour install, with normal breaks to answer the phone, nature calls, and to replenish necessary body fluids.

 

General Disclaimer – This guide presumes that you 1) Are comfortable working on your car, and that you have the appropriate tools and time to complete this installation; 2) That you will take adequate safety precautions while engaged in installing this product, and 3) If you have any questions or concerns about installing this product, that you will seek qualified assistance before proceeding with the install. As GrimmSpeed indicates in their literature, this product is intended for off-road use only, so use accordingly.

 

Posted the .pdf on ScoobyMods here

Prep 1 – Gather your tools.

 

As a minimum you will need:

 

• 15mm open-end wrench
  
• 5mm Allen wrench
  
• 1/4” or 3/8” drive ratchet - 3/8", then you'll also need a 3/8" knuckle joint
  
  
• 10mm socket (deep well works best)
  
• 10mm offset box-end wrench
  
• Work light
  
• Protective latex or nytril gloves – a lot of scrape points and the additional “grip” is definitely helpful. Heavy mechanics gloves will not fit into these tight spaces
  

 

Also helpful but not really necessary

 

• Magnetic pickup with extension - this was a real time-saver and in one case meant the difference between locating a dropped bolt inside the cross-member, or stopping the install to buy another bolt
  
• Magnetic catch pan - handy for holding everything
  
  
• A good microfiber towel to put between the top of the strut tower and the fuel pressure regulator setup to keep from scratching the paint - you'll want to put something between the car and the FPR setup
  
  

 

 

 

 

Prep 2 – Park your vehicle on a level surface, set the parking brake and chock the wheels to keep the car from rolling.

 

Prep 3 – Locate the master cylinder – This shows the general layout of the Subaru master cylinder, the fuel pressure regulator mounting attachment points and the general area where this brace will be installed.

 

 

Prep 4 – Locate the fuel pressure regulator mounting bracket. It is located on the Driver’s side strut tower immediately adjacent to the master cylinder. This is where you'll install the MCB.

Step 1 – There are four bolts holding the fuel pressure regulator mounting bracket to the strut tower. Two are located on the very top as indicated in the first picture.

 

And two are located on the side, closer to the firewall as shown in the second picture. As noted in the second picture, the STI Gauge Pack installation attaches the Defi Boost Pressure Sender to the bottom bolt on this side of the bracket. The MCB comes with new, shorter bolts for these two locations, so if you don’t have this item, then you will use the two MCB bolts and will not have to reuse the stock bolt which is longer than the MCB bolt.

 

Once you have these four bolts out of the brace, gently lift the entire fuel pressure regulator setup up, out, and away from the strut tower.

 

At this point you will want to undo the two additional bolts that hold the remainder of the fuel pressure regulator setup to the regulator mounting bracket. This will give you more mobility and access to the strut tower mounting points and enable you to more easily position the MCB for install.

 

 

Step 2 – Once you have removed the fuel pressure regulator bracket, you will need to undo the cable support bracket from the strut tower. The MCB will use these mounting holes (using the two supplied longer bolts).

The second photo shows the fuel pressure regulator bracket removed as well as the cable brace. Recommend you disconnect the cable brace from the cable mounting point. This will make it a lot easier when it comes time to install the MCB and you need to be able to move the cable brace around behind the MCB.

Step 3 – The cable brace has side lobes (I call them wings) that inhibit the MCB from mounting flush to the strut tower. These photos show the initial fitting, the modified cable brace and the MCB installed flush to the strut tower.

 

You may need to recheck the fitting to ensure that the cable brace now lies flush against the back of the MCB. Note long bolts go through the MCB and the cable brace into the strut tower.

 

Note: Installing the cable brace on the front side of this location creates two issues – hence the need to modify the brace. The first is that the cable is now approximately ½ - ¾ inch closer to the engine and the radiant heat. The second is that the brace thickness behind the MCB is critical to keeping the MCB bolt and cup alignment perpendicular to the end of the master cylinder.

 

Install the two bolts on the firewall side of the brace, reattach the cable connector to the cable brace, and you are ready to install the actual master cylinder bolt, lock nuts and cup mechanism.

Step 5 – Using the first picture and working from left to right, feed the bolt through the MCB hole, ensuring that the Allen hex end is to the left and the indented end is to the right.

Chose one of the two supplied nuts and thread it on the right side of the brace, leaving enough bolt extended to attach the cup.

Thread the second supplied nut onto the bolt on the left side of the brace leaving it slightly loose.

 

Place the MCB cup at the indented end of the bolt, and using your fingers and turning it clock-wise, to the right, feed the bolt toward the master cylinder until the MCB cup contacts the end of the master cylinder and snugs up.

Following the second picture, insert the 5mm Allen hex wrench into the left end of the bolt and hold it firmly in place. Using the 15mm open-end wrench, tighten the nut on the right side of the brace clock-wise (to the right) approximately 1/2 – 1 full turn more.

 

Again, using the Allen hex wrench, hold the bolt in-place and tighten the nut on the left side of the brace clock-wise (to the right) to lock the bolt and cup into place. Ensure the cup is squarely and firmly against the master cylinder and that there is no play.

Step 6 – Button everything up, making sure that no lines are crimped, pulled-off or otherwise mis-aligned. Pay particular attention to your vacuum and fuel line connections to make sure that there are no loose connections, or cracks, seepage, or leaking from any of the fuel lines. Make darn sure that you have checked your vacuum line to your fuel pressure regulator - the one that comes directly off the side of the intake manifold - and that it's properly fitted to the manifold.

 

 

I apologize that some of the pictures are fuzzy. I didn't realize at the time that humidity was fogging up the lens.

 

Overall, the installation was pretty straight-forward, once I figured out that I'd need to amend GrimmSpeed's installation guide to match the Legacy's different FPR mounting setup. You could probably do this in about and hour and a half, but would allow at least 2 hours just to be on the safe side.

 

I used 1/4" drive bits, it just made it a lot easier getting into the tight confines, without having to resort to a 3/8" setup with knuckle joints to make the turns. The 1/4" drive really worked well. I tightened everything down really well and will go back later and re-torque everything again.

 

From a test-drive perspective, I knew immediately as soon as I put my foot on the brake pedal, to start the car, that things had "tightened-up" in the pedal. I did a couple of miles at highway speeds and several stretches of city streets, the change is remarkable - braking onset is more stable and predictable. I've not gone to SS brake lines yet, but IMO, this likely got the braking action to what one would expect with SS lines.

Well-done to GrimmSpeed for a quality product. Fit was spot-on and required very little effort to get everything lined up and reconnected, even with my big ham fists. And the braking difference was well worth the wait on this.

 

For additional install information, please review the GS MCB install guide for the 08+ WRX. Here is also the link to their

Subbed. Would this walk through be essentially the same for us 08-09 VDC'd Leggys?

The braces are different as I understand it, but the location and bolt-up may be similar.

Nice write up!

 

Thank you sir!

Nice write up!

 

Thank you sir!

 

+1 thanks, SBT!

Nice write up!

 

Thank you sir!

 

Thanks SBT! Great stuff!

Very nice sir. Well done!!!

Subbed. Would this walk through be essentially the same for us 08-09 VDC'd Leggys?

 

I believe the MC brace itself will be a slight different design for us VCD types, but like SBT said the location will be the same.

Nice writeup, as usual!

 

You should've put it in the Walkthroughs!

It's craaaaazy what that brace does for pedal feel, isn't it?! Makes pushing that brake pedal so much more enjoyable when you have to use it

Step 3 – The cable brace has side lobes (I call them wings) that inhibit the MCB from mounting flush to the strut tower. These photos show the initial fitting, the modified cable brace and the MCB installed flush to the strut tower.

 

Note: Installing the cable brace on the front side of this location creates two issues – hence the need to modify the brace. The first is that the cable is now approximately ½ - ¾ inch closer to the engine and the radiant heat. The second is that the brace thickness behind the MCB is critical to keeping the MCB bolt and cup alignment perpendicular to the end of the master cylinder.

Thanks for the excellent writeup! Just thought I'd chime in here to say that mounting the brace to the front of the MCB is an option for those that would prefer not to modify their OEM brace. Our installation instructions will also mention that you're free to remove the bracket all-together and use a ziptie to secure the wiring harness (as is done on some of our other models).

 

Cosmetically speaking, we'd love to see that red cup centered on the MCB, but functionally speaking, you've got some wiggle room there. In our testing, we found chassis geometry to differ a bit from car to car, so there should be plenty of room for you to get 100% effectiveness out of the brace in any configuration.

 

It's a tough improvement to really explain in words, isn't it? It just feels right!

 

Subbed. Would this walk through be essentially the same for us 08-09 VDC'd Leggys?

It will be a very similar install. In fact, you guys seem to have more room up there and in my experience, it'll be a quicker install. Note that your car will require a different brace, but that it's in development right now and should be available shortly!

 

Matt

Engineering

Matt - thanks for chiming in on the cable wiring brace. Without the wiring brace behind the GS MCB the brace face alignment to the master cylinder was off ~ 1/8"-3/16" inch. More: "\ |" looking if you will... Once the wiring brace was modified slightly, and reinstalled behind the MCB mount, the brace face was square and true to the master cylinder and the alignment looked like this: "| |" which my OCD nature responded to much better.

It will be a very similar install. In fact, you guys seem to have more room up there and in my experience, it'll be a quicker install. Note that your car will require a different brace, but that it's in development right now and should be available shortly!

 

Matt

Engineering

 

Shortly as in a potential Christmas present for the customer who has faithfully bugged you guys about this part?

 

I believe the MC brace itself will be a slight different design for us VCD types, but like SBT said the location will be the same.

 

And I was all excited to buy today... Oh well.

 

Please let us know the second we can buy the VDC model.

 

Thanks!

If I had not put so much recent effort into getting the TMIC-to-TB hose on, tight and leak-proof, I'd have taken off the intercooler and accessed everything from the side instead of predominantly from the top. I think that would subtract at least 30 mins from the install because it would be that much easier IMO to do this install when everything is that more accessible.