Real Fiero Tech

Wanting to do the brakes on my 88 and i see that the master cylinder are no longer available. What would a good solution for a replacement? I plan on staying with stock calipers with larger rotors in the future. Something that can replace the stock one without awakening the ORGE. I am getting the calipers rebuilt and wave replaced the lines both hard and soft.

The early 84-87 master cylinders look like they would drop in, but they have a 1" bore vs. the 0.937" listed for the 88.

The brake pedal would require slightly more effort, but it would feel firmer too, which might not be a bad thing.

Ogre often considers the insurance implications of tampering with brakes, but it would take a hell of an insurance investigation to disassemble the master cylinder to measure the bore with a telescoping T-gauge. Buy with cash if you want to avoid a paper trail.

Thank you, I knew there is a simpler solution.

Why are you wanting to replace the master, are you having issues with it? When I starting getting mine back on the road I Ordered a new master for mine as it just didn't seem like it was applying enough Hydraulic force. While waiting for new flex hoses to arrive I replaced the Brake Booster. I didn't install the new master at that time cause well, why bleed the brakes twice.

Trying the car with the new Booster The braking was transformed. I never did replace the master, doesn't feel like it needs it now.

The '88 MC has a "quick take-up" feature in the form of a stepped piston, doesn't it? This is to reduce free-play in the pedal while pushing the pistons in the rear dual-action (hydraulic service brake + mechanical parking brake) back into contact with the rotors. The fronts apparently don't have as much knock-back because they're hydraulic only.

The larger bore of the early style MC will definitely result in a higher pedal, but also greater effort.

There's also the "S10 booster upgrade" which sounds fairly simple. The booster increases line pressure for a given pedal force, increasing brake torque per unit pedal force. The booster also has to be working correctly. Fiero brakes aren't great stock, but they really suck if the booster isn't working correctly. The upgraded booster makes them a bit better.

Higher line pressure works wonders for small brakes. Mercedes-Benz W211 E-class cars with the Sensotronic Brake Controller (SBC) have 295mm front rotors (11 5/8") despite being 3800-4000# sedans, and those brakes flat WORK. When the SBC developed reliability problems and Benz removed it in favor of a conventional brake system, they had to step up to 330mm front rotors in order to get the same pedal force to brake torque relationship that the SBC gave them with 295mm rotors.

I don't know the math, but i did the S10 brake booster on a 12" rotor stock brake 88 and I can't explain it other than when I or anyone has pressed on that brake pedal, it just feels like pressing the brakes on a car built within the last 10 years. I cant say it brakes harder or what, it just feels better, it feels like what we drive daily