i bought my 89 civic 4dr about 3 months ago and mechanically, it was good except there was an overheating problem. well after a week of troubleshooting, it turns out it was the water pump. the dumbass that owned the car before me ran 100% water in the cooling system for god knows how long and everything corroded. anyways, thats a little insight on the prior owner. so a little over a month ago i changed my brake pads in the front, at the same time i checked the brake fluid and it was a little low, so i added to the full mark. well today i go driving and the brakes have more play than usual and theyre spongy. so i check the fluid and the reservoir is empty. i check the master cylinder for damp spots, none. im thinking, i must be leaking from somewhere but at the moment, i cant check the calipers or drums. so for the hell of it, i fill the reservoir back up and pump the brakes a bunch of times i can feel the pedal getting stiffer and stiffer, i go drive around and the brakes are back to normal. im thinking, if the master cylinder ran so low that air got in the system, then simply adding fluid wouldnt fix the problem, but it did. so im wondering if the seal on the reservoir cap is worn and the fluid is evaporating(if thats even possible).





Modified by Hizzle at 3:34 AM 5/13/2004

 

well, i just did a little research on the net and found out that brake fluid does not evaporate, so i guess i do have a leak somewhere. i guess the fluid got low enough to affect performance but not low enough to run the reservoir dry get air in the system. even when the brakes felt spongy, they would still work ok, pretty decent actually, just not as good as normal(i tend to notice the slightest things, especially when it comes to car stuff).

 

The older 88-91 Civics did have problems with the wheel cyl's leaking. This would definately cause a spongy pedal if the leak was big enough. Check everything and let us know what you find.

 

agreeing with above the wheel cylidners should be replaced everytime drum brakes are being serviced which isnt very often but you get the point, os the guy running 100% water prolly didnt repalce them

 

If you lost that much fluid, you can probably tell which wheel it is leaking from by bending down and looking at the INSIDE of each rim.

One will look wet/oily.

 

true, i havent looked yet. i talked to one of my friends, he says that its probably leaking internally inside the MC. what does that mean? that fluid has to be going somewhere. theres no wet spots on the MC or brake booster and if it were leaking that much inside the car, i would notice because the pedal would be oily or it would smell.

 

if you dont find any leaks, the fluid is probibly inside the master cylinder, there are two parts to it and it is more than likely almost full of fluid, it will blow out soon, if thats where the fluid is.