Fox Body 4 Cyl. To V8 Brake Line Conversion Guide | 1979-93 Mustang

Brake Line Conversion Steps

1. When converting the four-cylinder Fox Body Mustang to a V-8. You will also need to add the dual exhaust system and upgrade to the 8.8 rear end. The original four-cylinder brake line that goes to the 7.5 rear axle, is located where the new exhaust system needs to be routed.
At the rear of the 4 cyl. brake line there is a bracket that bolts to the body on the passenger side. This is where the muffler hanger is mounted on the V8 cars. This area is the reason that this must be replaced with the V8 brake line setup.

2. Converting the brake line and bracket to the 8.8 requires removal of the original four-cylinder brake line and replacing it with the V8 Brake lines and bracket. You can start by removing the right front tire and the inner fender liner to gain access to the brake line where it enters the right rear corner of the engine compartment. Please Note: The intermediate line that we sell doesn't include the brass union that is shown in the first image below. We do sell an alternative option for all 1979-93 Mustang models (LRS-785437).
The splice at the right rear corner of the engine bay is the beginning of the brake line that ends at the rear of the drive shaft tunnel.

3. The clamps holding the brake line to the body are secured with pop rivets or screws.
Under the car the brake line comes from behind the passenger side inner fender splash shield.

4. These pop rivets must be drilled in order to release the clamps from the body.
The line is routed along the passenger side frame rail with riveted clamps Transitioning from the frame rail to the pinch weld and shares a riveted clamp position with the fuel vapor line. At the rear of the pinch weld, the brake and vapor line again share a rivet clamping the two lines to the body. The two lines turn back to the rear frame rail and have a plate that clamps and protects these lines at the vulnerable area under the frame rail. At the rear of the 4 cyl. brake line there is a bracket that bolts to the body on the passenger side. This is were the muffler hanger is mounted on the V8 cars. This area is the reason that this must be replaced with the V8 brake line setup.

5. The two brake lines are routed identically until you get to the rear area where the line is directed to the driveshaft tunnel and a bracket mounted just to the left of the tunnel. You will need to install the new rear attaching bracket.


6. The replacement brake line has a shipping bend that must be straightened before installing.