Spongey Brakes and "Stop Lamp"

[benjamachine]

Hey all! 

 

I've been having this problem for some time now. The brakes on my '87 Subaru GL 4WD wagon are just terrible (not as snappy as the ones on my old '86 GL FWD). The pedal is a liiiittle spongey, and the "stop lamp" light comes on half the time when I depress the brake pedal.

 

Here's what I've done to fix:

 

-replaced master cylinder, front hoses, calipers, rotors and pads

-replaced hill holder (the old one was leaking) and disabled the mechanism

-bled brakes in factory-correct X-pattern

-checked rear brakes for leaks... nothing!

 

I'm at a loss here. Also, when I bled the brakes, I often didn't get fluid out of one side or another after a while. Where could the hole be? Doesn't look like I'm losing fluid or anything.

 

Thanks, -b

[Knucklehead Saloon]

Sounds like a crack in one of the metal lines that run off the master cylinder.

 

When you get no fluid from a brake bleed which wheels exactly do that ? If its just the fronts or just the rears then that will narrow down your search as to which hard line is leaking.

 

If both fronts and backs are doing it then its a mastet cylinder problem ( I know you replaced that but check to see if brake fluid is leaking into the brake booster from the rear seal)

 

Cheers.

[jsyme]

It still sounds like there is air in the lines. 

 

This time bleed the brakes in factory-incorrect farthest-wheel-from-the-master-cylinder-first process <one wheel at a time only>, and attach a clear rubber hose (3/8" ID?) to the bleeder valve captured inside a 1 liter plastic bottle.  just leave that valve open and pump some brand new DOT3 through it like a madman.

 

If you're really clever you might find a way to make a change of color (blue) in your reservoir, and once you see that in your bottle, you know you've done a complete fluid replacement in that line.

 

Rinse and repeat 3 more times, and then come back and tell us how happy your are and take a picture of the bottle jig you used.

[Gloyale]

for what it's worth, the stop lamp is indicating that one of your bulbs is defective.  It checks for balance of resitance between the 2 brake light bulbs.

 

the fact it's coming on for just a moment indicates probably a rusted bulb socket with alot of resistance.