Manufacturer: ChaseBays


• Full kit replaces the OEM brake booster and master cylinder.
• Weighs in at 1.38 lbs. Easily eliminates 20+ lbs.
• Includes properly designed black anodized aluminum firewall plate, stainless steel mounting hardware, black Wilwood 7/8ths Master Cylinder, -3AN 90º output fitting, and rod end pedal adapter with attachment nut
• Aftermarket brake pads required, Hawk HPS equivalent or better (explained below)

How will this effect the way my brakes feel? Why do you use a 7/8" master cylinder instead of a 1+ inch?

The common hearsay of eliminating the booster is that the pedal is too stiff for reasonable braking control. This is due to improper design and setup 100% of the time. The key to great pedal feel and more controlled braking is a properly sized master cylinder in relation to the pedal ratio used and an adjustable proportioning valve in between the rear brake lines. (Pedal ratio is simply referring the length from the pedal swing mount to where it attaches to the master cylinder). This includes larger sized front and rear calipers, they work perfectly fine with this setup. Rest assured, Chase Bays has you covered. You can get everything you need to properly set up your vehicle in one place.

Bigger is not always better with braking components. Increasing the diameter of the master cylinder bore will reduce line pressure, which also reduces clamping force. This is why aftermarket pads are required; the OEM pad compounds do not react quickly enough for the rapid clamping force. If a 1” bore master cylinder were used with the OEM pedal and no brake booster, pushing the pedal would be too stiff to allow the car to brake properly. Braking is more raw without the brake booster. Meaning there is less room for error on a poorly designed setup. If designed properly, the Chase Bays Brake Booster Eliminator yields a very pleasant brake pedal feel not far off from what you’re used to. All while still allowing the braking system to function normally and adding the feature of consistent braking.

The pedal ratio needs to be matched to the master cylinder output volume. Its what directly effects how your pedal feels and how your braking functions. With all the main chassis we specialize in, the 7/8ths master cylinder has been a perfect match for the OEM pedal ratio.

Bigger master cylinder = Harder pedal feel/more difficult to push and shorter travel.

Smaller master cylinder = More soft pedal feel/easier to push and longer travel.

How does the number of master cylinder outlets factor with braking power?

Brake pressure output is determined by the master cylinder bore size. Vehicles with up to 4 outputs on the master cylinder have a pressure output that is controlled internally by the bore size. The increased number of outputs does not translate to more braking power.

Will this product be able to stop my car when I'm going 140mph or heading into a turn at 120mph?

Absolutely, we have many cars running this setup stopping under even more extreme conditions. Functionally the car should experience the same braking times and distances. If setup with our Brake Line Relocation Install Kits and/or as we explained in question 1, they should perform exactly the same. Not only have we tested the kit ourselves for over 5 years, but we have also sold them to over 1000 customers who have continued to leave outstanding reviews.

What chassis does this item fit?

This kit is mostly universal for European chassis. It fits the 4-bolt pattern thats common with BMW, Audi, Porsche, VW, and more. IMPORTANT: THIS ITEM DOES NOT DIRECTLY FIT BMW E36/E46/E90/E92. Stay tuned as we are working on plates for those now. We offer 2 other brake booster eliminator kits to fill the gap. Toyota/Lexus and Japanese/American car Brake Booster Eliminator since those bolt patterns are different. 

Compatible with or Confirmed to fit:
BMW 2002
Porsche 944
Porsche 928
1990-1999 Volkswagen VW

Not compatible with/ Doesn't fit (Plate coming soon that does 1/1/2016)
BMW E92Does this kit work with my OEM brake lines?

No. You can purchase one of our supported chassis Brake Line Relocation kits to assist you with installation. If we do not make a Brake Line Relocation for your chassis, we've created a solution utlizing a Combo kit and Custom Length Brake Line assembly. Make it Combo! (Click HERE for more info). The reason it doesn't work with OEM lines is due to the master cylinder being a single outlet design instead of dual/triple/quad like most OEM master cylinders. A common misconception is to believe this causes a higher risk of failure due to a lack of a back up line should one line fail and rupture. Most OEM master cylinders are still single feed internally would pose the same assumed “risk” to our Wilwood Master Cylinder. The way to avoid this is by not poorly assembling and installing brake lines that have a high risk to burst or break. We have found if you use OEM quality or higher brake lines, this risk is eliminated. Chase Bays Brake Lines are mostly 37º flare, which is a step up from the OEM 45º flare. 37º flare is the standard in the aviation and military industry. Still, even with dual output master cylinders and Bosch Motorsport ABS unit, if a brake line burst or is damaged you have the exact same risk...we know this from direct driver experience!



  • Anodized Black Aluminum
  • Adjusts the Brake Bias between the front and rear brakes
  • 1/8 NPT outlets
  • INCLUDES (2) -3AN adapter fittings

Pressure adjustments range 100-1000 PSI and provide for a maximum decrease of 57% in line pressure.  This adjustment allows you to fine tune the front to rear braking balance by proportionately decreasing the rear (or in some cases the front) brake line pressure. This product in most cases requires custom brake lines.
The adjusting knob rotated all the way out will provide a maximum pressure reduction of 57%. Rotating the knob in will incrementally increase line pressure, up to full pressure. If the range of adjustment in the valve is not sufficient to properly balance the vehicle’s bias, changes to other components within the system may be necessary.

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