Abnormal brake operation

[cciornei]

Hi,
My 93 Festiva automatic is driven daily by my wife and she told me that sometimes the brake pedal will travel all the way to the floor and the car will not brake/stop but after few breaking action on the pedal (pedal pressings) the brake will come to a normal operation mode. Looks like the car is not safe to drive and I would like to know what can be wrong. I suspect the master cylinder – if anyone can confirm that. Thanks

[WTFestiva]

Check the brake lines as well. I had a cracked line on my S-10 a few years back and it was leaking fluid. Sometimes the pedal dropped to the floor, other times it worked unless I really pumped it.

[georgeb]

Try flushing and bleeding then try it in a safe place. If it still does it replace m/c. There 40-something$.

[FestYboy]

^ MC

[Movin]

^^ plus 1 !

[WmWatt]

The brakes work by hydraulic pressure on the brake fluid in the system. If air gets into the system there is not enough hydraulic pressure to push the pads against the front rotors or rear drums. You have to get rid of the air. First try to find the leak by looking for wet brake fluid along the metal brake lines under the car and around the wheels, and fix the leak. Then you have to unscrew the valve at the wheel and let the air out and replacement brake fluid in. The brakes have a safety feature, a "combination" valve, on the firewall in the engine compartment which "turns off" one front brake and one rear brake if either is leaking, so the car can stop using the remaining front and rear brake. Consequently if the brakes aren't working it usually means two leaks. The owner's manual recommends inspecting the brake lines for leaks periodically because the valve may have shut one pair down due to a leak and you are vulnerable to a leak in the other pair.

[WmWatt]

I forgot about the master cyclinder, or pump, which applies the pressure. If it's worn or the brake fulid is low in the reservoir you could also get "abnormal brake operation". The master cyclinder is in the engine copartment in front of the driver. The plastic reservoir sits on top of the master cyclinder. The level of the brake fluid in the reservoir should be at the mark.