I'm Unidiagonalling!

[Safety Guy]

My brake pedal is almost to the floor and when I braked hard, it felt weird.

After getting out and feeling the front wheels, I now know what's happened: I've lost half my brakes! The left wheel was warm but the right one was COLD. No friction=no caliper action.

During light and regular braking, it felt okay. No trouble lights came on.

The master cylinder is full of fluid. No loss there.

What would have caused this? I'll be checking my shop manuals later today. Would this be a bad master cylinder or something leaking from half the system? The fluid is pretty high, though. I don't think any was lost.

I always thought when there was a serious problem that the brake light would come on.

No time to fix it now. I'll just drive slower! And be ready with the handbrake.

Aspire brakes do pretty well even when they're half gone!

Karl

[Kraig]

Piston stuck in caliper
Clogged brake line

[skeeters_keeper]

piston stuck, or if its just been happening since its been freezing out maybe you've got watter in the line thats frozen now.

I don't think there is a brake light on our cars?

[Safety Guy]

Thanks guys. "Piston stuck" could be it.

I'll have to forgo using the handbrake for awhile to see if the LR drum heats up. If it does, the problem is localized to the RF disc. If it's cool and the RR drum is not, then the problem could be a clogged brake line near the master cylinder.

It hasn't frozen yet, temp wise, so that's not it.

I was thinking of our handbrake light. I thought it served several functions. One of which should be warning of very low brake fluid?

Thanks again!

Karl

[5.0zone]

A quick way to test if the piston is stuck or if the line is clogged.
Open the brake bleeder for that wheel and hit the brakes real hard.
If the peddle drops to the floor and lots of fluid comes out, then the piston is probably stuck.
If the pedal remains firm and only a little fluid comes out the the line is probably clogged and the most likely culprit would be the rubber line to the caliper.

[Festiva_tunner]

A quick way to test if the piston is stuck or if the line is clogged.
Open the brake bleeder for that wheel and hit the brakes real hard.
If the peddle drops to the floor and lots of fluid comes out, then the piston is probably stuck.
If the pedal remains firm and only a little fluid comes out the the line is probably clogged and the most likely culprit would be the rubber line to the caliper.

AFTER DOING THIS BLEED YOUR BRAKES!

you will suck air into the lines

you can get a peice of 1/4" ID flexible clear line and run it into a bottle (clean soada bottle works) put some fluid in the bottom of the bottle and stick the hose into it, mark you fluid level, then install the line onto your bleeding screw after loosening

mash the with your hand while looking at the bottle, note the fluid amount over your indicator line, this method is less messy and will prevent air from getting into your system

[FestYboy]

the brake light on the dash is a 2 function light (hand brake AND fluid level)

not flushing your brake fluid every 2-3 years like you're supposed to can cause this problem. as the fluid ages, it collects water and contaminants from the rubber parts that it touches breaking down (brake fluid is acidic, it can strip paint) as it collects water (brake fluid is also hydroscopic), the water oxidizes the fluid and anything the fluid touches. rust, hardened seals, broken seals due to rot, these are all things i see every day because of lack of regular maintenance. expensive repairs soon follow.