Installing The New Schnell Autosports Exclusive 981/991 Brake Master Cylinder Brace!

We're excited to show off our latest product that we have in production, our brake master cylinder brace!

If you have a 981 or 991, your braking performance isn't the best it could be.

Under heavy braking, your firewall will actually flex from the pressure, which allows your brake master cylinder to move. As with brake lines, any unwanted movement in your braking system means that you're reducing brake pedal feel and responsiveness, because the force that's being used to flex the master cylinder, is force that's not going to your calipers.

You can see this movement for yourself in this quick video we made:

Our master cylinder brace is designed to remove the majority of that deflection, by bracing the master cylinder to another point on the car (in this case, the wall that separates the front luggage area from the rest of the front trunk area). With that deflection removed, you'll be able to brake harder, and improve your pedal feel.



Installation is simple, and you can do either the "basic" installation using tension only, or you can opt to do the "full" installation, and attach the wall-side of the brace to the luggage compartment wall via the provided screws/nuts to give the brace a more secure fitment.

Please note: from our research, it appears that there are two different master cylinder designs. At the time of this writing, our master cylinder brace will only fit one of those types. Please see the following image, and compare it to your master cylinder:

There appear to be two different master cylinder designs being used right now. The type with the end that is mostly round (pictured) is what this brace is designed for. This will not fit on the master cylinder brace that has multiple protrusions on the end.

Master cylinder brace kit. A 16mm and 19mm wrench are needed for basic installation; 3mm Allen key and 8mm socket wrench are used if you opt for a full installation.

At the most basic, the brace consists of 3 main parts: one end plate that goes against your master cylinder, one end plate that goes against your luggage compartment wall, and a turnbuckle screw (with jam nuts) that connects the two end plates and allows for tension adjustment. When you order the brace, you will also receive 4 button head cap screws (3 long, 1 short), and 4 nylon locking nuts, but we'll touch on those later.

The first step is to assemble the main components of the brace. We suggest turning the jam nuts inwards towards the center nut to give you more room to work with when you go to install the brace in the car.

Keep in mind that one of the end plates (the plate that goes against the wall) and one side of the turnbuckle bolt is reverse-threaded, so if it doesn't seem like the bolt is threading into the plate, try the other side.

Lefty-tighty, righty-loosey will confound your brain while you do this. Also: note the jam nuts turned in towards the nut.

With the turnbuckle bolt installed on both ends, rotate the center nut so that the ends of the turnbuckle thread into both end plates, and overall length is reduced. This will make it easier to position your brace when you go to install it.

The overall length can be made shorter or longer by rotating the center nut.

After opening your hood, unclip the top cover, and either remove it completely and set it aside, or use the built-in hook to keep it held up and out of the way.

For those of you wondering what that yellow piece on your cover was for, here you go.

For us, we found it easier to position the wall-side end plate first. The flat section with the "Schnell Autosports" text is the top of the plate, and should be pointing upwards. Place it against the luggage compartment wall, making sure that it is not sitting on any wires or cables. Position it as best you can so that it aligns with the master cylinder, but you don't have to be perfect with it, as you can adjust it more as you tension the brace later.

With the brace more or less in position, start rotating the center nut on the turnbuckle bolt to extend the brace, so that it makes contact with the end of the master cylinder. The cutout on the master cylinder side end plate should line up with the master cylinder brace so that the protrusion for one of the brake lines on the cylinder clears the notch, allowing the end plate to sit flat against the master cylinder.

The cutout on the end plate should line up with the brake line fitting.

You may have to hold onto the end plate once it is lined up, to keep it from rotating as you rotate the turnbuckle bolt by hand.

There is a black electrical connector just to the left of the end of the master cylinder. When installing the end plate, you will have to slightly move it to the side to allow clearance. Make sure that the end plate is not pushing against the connector as it seats against the master cylinder, or you may damage the connector.

Be mindful of the black electrical connector to the right of the master cylinder. It can be pushed slightly to the left to prevent interference with the brace.

With the brace in position, you can now begin to tension the brace so that you can limit the deflection in the master cylinder caused by hard braking.

The center nut is 16mm.

Turn the nut counter-clockwise (if facing the master cylinder) to lengthen the brace, and tighten it until you feel firm resistance.

With the main bolt tightened, tighten the jam nuts. Spin them by hand until they are against their respective end plates, and then use a 19mm wrench to snug them down. Keep in mind that these will rotate in the opposite direction that you used to tighten the turnbuckle itself.

Both jam nuts are 19mm.

Once the jam nuts are snugged against the end plates, your basic installation is complete! You can either choose to be done here, or you can continue on with the "full" installation, which has you attaching the wall side plate to the car via the provided button head screws and locking nuts.

If you decide to only do the basic installation, go for a few quick drives, and then check the tension of the brace. You may find that it will need to be tightened a little more, and it would be good to generally check on it periodically.

The full installation is admittedly a firm commitment. You will be using your wall-side end plate as a template to drill 4 holes into the wall of your car, so that you can use the button head screws to give your brace a more solid mount.

To drill the holes, you will need a drill, a right angle drill attachment, and a 13/64 drill bit or equivalent.

Before doing that however, you will need to move the trunk lining out of the way, both to prevent damage to the liner, and to give you access to the screws so that you can attach the nuts.

First step is to remove your tow hook storage box. This is simple to remove, just grab the box via the grab handle, and pull outwards. It is connected by push pins on the side where the handle is, and attaches via a tab and slot on the opposite end.

The liner can now be pulled forward. Just feel for the edge underneath the rubber trunk seal, and you should be able to get a finger behind the liner and pull it away from the wall.

You can now use your installed brace as a template to drill the 4 holes needed to attach the plate. Pretty straightforward, and the right angle attachment is because you have limited space to work in.

This is going to be the most terrifying part of this installation.

Once you have the holes drilled, you can insert the screws. The kit comes with 3 long screws, and 1 short screw. The short screw goes in the bottom right hole (if facing the brace; it is the bottom left hole if facing the wall), and the longer screws go in the remaining corners.

In this picture, the bottom left screw is the short one.

With the screws in place, you can secure them with the locking nuts. Take a 3mm Allen key, and insert it into the head of a screw to keep it from rotating, and thread the nut onto the screw from the other side. It helps to start the nut by hand first (to prevent it from being dropped), and then use an 8mm socket wrench to tighten it the rest of the way. The nut only needs to be tightened until snug. Repeat for the remaining screws.

We also found it helpful to put tape (in our case, painter's tape) along the edge of the trunk liner, as it can be somewhat sharp and uncomfortable to have your arm against while you tighten the nuts.

The nuts are only tightened until snug. Note the taped-up edge of the liner to make this a less obnoxious process.

With all the nuts tightened down, you're done, and you can tuck the liner back into place and reinstall the tow hook box. As with the basic install, take a few test drives and then check the brace tension.

With our brace installed, your master cylinder now will no longer move under heavy braking, and you'll have better pedal feel to boot!