Brake Problem

Bob Fano

New Member
Dec 31, 2013
I have a 69 mustang that I just installed 69 Disc Brakes on the front. I have an 89/5.0 EFI set up in the car and used a master cylinder and brake booster from the 89 Mustang. While it had drum brakes, everything worked great. When I just did the conversion, no matter how I bleed the system I can't get any pedal. I have installed a new master cylinder and brake booster. I have the original line block from the 69 and checked the line piping. What did I overlook?
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That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
Define "can't get a pedal"

The pedal is soft but stops the car..or you can pump the pedal and it barely stops the car.

Do you know the specs on the front calipers. Are these the 4-piston calipers put on 60s mustangs, or something else?

Depending on piston size, it's possible the MC bore is just too small and you can't move enough fluid. You would need a larger bore MC to compensate.

Unsure if those calipers can be mounted upside down, another thing to check


10 Year Member
Aug 25, 2010
Unsure if those calipers can be mounted upside down, another thing to check

To put a finer point on this, calipers are side-specific, but they'll usually bolt on each side of the car just as easily as the other. But the position of the bleeder screws matters. It's a really common mistake when replacing calipers to put them on the wrong sides of the car so that the bleeders are too low, trapping air in the caliper above the level of the bleeders. When this happens, you will never get them to bleed properly and you'll be forever chasing a soft pedal.