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MM News

NASA Racers! MM will support NASA road racers with $1,000 contingency prizes for the American Iron, American Iron Extreme, and Spec Iron at the 2019 National Champions. You must register to be eligible.

New! Read the article Maximum Motorsports Tames Fox & SN95 Mustang Rear Suspensions on FordMuscle.com.

MRT Exhaust! MM now offers premium MRT cat-back exhaust systems for 1996-2004 Mustangs.

New! for Street & Strip Mustangs! Big-bore rear wheel cylinders for 1979-1993 Mustang with 9" drum brakes. Improves braking when running big rear tires and front skinnies, and/or different OEM front brakes.

New! Swapping a Coyote into a Fox Mustang? MM's Hydroboost Conversion Kits allow easy installation of a 1996-2004 Mustang Hydroboost power brake assist unit into a 1979-1993 Mustang.

New! Swapping an IRS into your Fox Mustang? MM makes it easier with a brake line kit made just for this conversion. Bolts-in, with no cutting or flaring of brake lines. Designed to fit standard IRS brake hoses.

New! MM's billet aluminum Pedal Box Spacer for Fox Mustangs. Replace the breakage-prone OEM plastic spacer when converting to manual brakes or Hydroboost.

Canadians! Please read the latest about ordering from Canada/shipping to Canada.

We've posted the parts list and link to the video of MM's Mustang in /DRIVE Tuner car Shootout

Brake Proportioning Valve Plug, 1979-2004
Actual product may differ from photo.


  • Item # MM-2450-A


Larger Image

Plug used to disable the stock brake proportioning valve when an adjustable valve is installed

What is this product used for?
The stock brake proportioning valve must be removed or disabled whenever an adjustable proportioning valve is installed. There are two ways to do so:

  1. Remove the stock valve with MM's Brake Proportioning Valve Eliminator Kit (MMBAK-6)
  2. Disable the stock valve by removing the internals and replacing the stock valve's cap with this plug.

This product fits

  • Direct bolt-in fitment to 1979-2004 Mustang

This kit includes:

  • Solid plug
  • Sealing O-ring
  • Illustrated installation instructions


Product Features

  • Precision-machined solid plug threads into stock proportioning valve.
  • Includes a new sealing O-ring, unlike the original FRPP plug that reused the original O-ring.
  • Includes illustrated installation instructions, unlike the original FRPP kit.

Read the installation instructions for the MM-2450-A brake proportioning valve plug.
View the adjustable brake proportioning valve (BPV-1).