88 Fiero Master Cylinder fountains, little or no brakes. (Page 1/1)
tcharlton FEB 13, 11:35 AM
New E-brake cables installed and adjusted.
Replaced all brake lines.
New pads front and rear.
Bled all lines, no air in system.
Brake pedal seems good with engine off, but go to the floor when engine starts.
No leaks in system.
Replaced master cylinder because the old one would fountain fluid several inches into the air when the brakes were applied. Tried 3 different cylinders, same effect.

Suggestions?
theogre FEB 13, 12:54 PM
All Fiero Master Cyl are a Quick Take-up unit & your "fountain problem" is very likely Not a problem but likely rear caliper or other problem.
See https://web.archive.org/web...ierocave/brakes4.htm & other brake pages.

While many pages are for older Fiero & somethings are different, 88 have same rear caliper piston problems.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 02-13-2024).]

fieroguru FEB 13, 07:26 PM
Pedal pressure is from the rear calipers.

Check the gap between the rear pads and the rotor. It should be about the thickness of a playing car. Any more and pedal travel will be wasted just moving the pads to contact the rotor.
theogre FEB 14, 12:09 AM

quote
Originally posted by fieroguru:
Pedal pressure is from the rear calipers.

Check the gap between the rear pads and the rotor. It should be about the thickness of a playing car. Any more and pedal travel will be wasted just moving the pads to contact the rotor.

W/ new pads even when have rear piston(s) bad won't cause pedal of the floor. Will cause Low Pedal but that isn't = to floored.

Likely Either still have air trapped or is leaking somewhere. Even if hard to see, leaking fluid should drip down on floor/ground.