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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.

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Brake Line Kit for IRS Swap, 1979-1995 Mustang
Actual product may differ from photo.
  • Brake Line Kit for IRS Swap, 1979-1995 Mustang

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  • Item # MMBAK-21
  • Manufacturer: Maximum Motorsports
Add MMBK9R hose kit



When you're swapping a Mustang Cobra IRS into a 1979-1995 Mustang, this MM brake line kit has the new brake hard lines you need to connect the stock solid-axle rear brake hard line to 1999-2004 Cobra IRS brake hoses.

  • Easy fitment to the 1986-1995 V8 Mustang chassis that was originally fitted with an 8.8" rear axle.
  • Non-V8 1986-1993 Mustangs and all 1979-1985 Mustangs require minor brake line re-routing and an additional short hard line extension.
  • Puts the new hard lines in a position to attach to stock IRS brake hoses or MM's braided stainless steel hose kit MMBK9R.

IRS brake hoses require either removal of the Fox Mustang bumpstop brackets that are spot-welded to the rear frame rails, or modification to the IRS hose assembly mounting brackets to clear the bumpstop brackets. 1994-1995 Mustangs do not have the same interfering bracket.

Related Parts
  • Easy-to-install kit.
  • No need to cut and flare the stock brake lines.
  • No need to bend or otherwise modify the stock hard line (1986-1995 V8) running to the rear brakes.
  • Allows use of stock IRS brake hoses or the MM stainless braided hoses.
  • 2 pre-bent hard lines
  • T-fitting
  • MM-designed bracket to securely mount the T-fitting
  • Cushion clamps to secure the new hard lines
  • Mounting hardware

When installing a 1999-2004 Mustang Cobra IRS, easy direct bolt-in to:

  • 1986-1995 5.0L Mustang (originally fitted with dual exhaust)
  • 1985 Mustang GT (originally fitted with 5.0L engine, 4v carburetor, and dual exhaust)
  • 1985.5 and 1986 Mustang SVO (originally fitted with dual exhaust)
  • MM's stainless steel braided hose kit for the IRS
  • Stock IRS brake hoses

Will also fit
With some additional work this brake line kit will also fit non-V8 1986-1993 Mustangs and all 1979-1985 Mustangs. These cars will require minor brake line re-routing and an additional short hard line extension because the original stock rear brake hose was not center-mounted.

We're working on FAQs for this product. If you have a question, please use our Contact Us page to email your question. We'll answer your question by return email, and also consider it for possible addition to this FAQ section.

You can read Maximum Motorsports' highly detailed MMBAK-21 Brake Line Kit installation instructions before purchase.