brake light on dash stuck on

Folks-

I had a brake line break on my SL2 (due to rust), at which time the
red "brake" warning light on the dash came on.

The brake line is fixed now, the air has been bled out of the system
and the pedal feels like it should now.

However, the red "brake" light is still on on the dash.
If I disconnect the connector at the master cylinder, the light goes
off. If I reconnect it, it goes back on.

What can I do to get this light to turn off??

Thanks!

 

Uhhh....Add brake fluid?

 

No, it's not low. I filled it up after the brakes were bled.

 

I can't speak for the SL2 but on most cars with dual braking circuits, if
there is an imbalance in fluid flow (or pressure) between the front and rear
brakes, the warning light will come on. Most I have seen will reset
themselves when the pedal is pressed and released all the way up (make sure
that the pedal is not binding and will return all the way). I saw one car
some time ago that the front or rear circuits had to be bled only slightly
to restore a balance. IIRC - I've also seen cars where the brake circuits
are diagonal and not front-rear. Sometimes you have to push the pedal down
hard for a reset.

The fact that you removed the connector from the master cylinder and the
light went off means that it is not the parking brake. That one light does
have several meanings - low fluid level, front-rear imbalance and parking
brake.

Did you bleed the entire system or just the line which you replaced? If it
was old enough to rust out, the entire system should be flushed till it
drains clear.

 

Yes, I bled the entire system after putting the new line on because
the fluid looked like coffee. I'm sure the level is high enough in
the master cylinder, and the pedal feels like it should now.

As you said, I also thought that once the balance had been restored to
the system, that the switch would reset itself and the light would go
out.

This car DOES have a diagonal braking system- I assume all Saturns
do. As a matter of fact I think all GM front wheel cars have had
diagonal braking systems since they first introduced the front wheel
drive X body cars in 1980.

As far as I know, only rear wheel drive cars have front/rear braking
systems. They had to do this because there is a higher percentage of
weight over the front wheels on a front wheel drive car, and if you
only had your rear brakes to save you, you probably couldn't stop the
car.

I could try stomping hard on the pedal, and also making sure if it
comes all the way back up (make sure it's not binding), and see if
that helps it.

 

Does the car have ABS? if so, that complicates it another level.
Sometimes you can unscrew the sensor in question. The balance switch is
usually a rod with pistons at both ends that is exposed to the brake
pressure in each circuit. The rod has a Vee groove in the center. Groove is
what the brake balance switch sits against. when a pressure imbalance
occurs, the pistons move the rod and actuate the switch. On some of these,
the rod is spring loaded to return to center when brake is released - others
it is free floating.

In any event, the rod may be stuck because of the old brake fluid. If you
can't free it up, a new part is needed.

 

You were refering to the connector attatched to the sensor in the brake
reservoir right? Thats a fluid level sensor... Either it see's fluid,
doesnt see fluid, or is faulty.

That lay out, diagonal split system, was determined to be the safest
overall. If one piston was to fail you will still have one front wheel
and one rear wheel on opposite sides stopping you. If you locked up just
the rear wheels or one side of the car you will almost certainly loose
control of the vehicle.

 

If it's a problem with the blake fluid level sensor, it's possible that some
crud that got the float stuck. IIRC, the float is magnetic and rides over
magnetic sensor. Try giving the reservoir a good rap to see if it gets
unstuck. Can't say for sure if the tank detatches from the master cylinder
to allow cleaning.

 

I will try tapping on the master cylinder to see if crud buildup is
holding the rod inside the M/C in the wrong position.

I guess if that doesn't work, I could try taking the master cylinder
off the car, disassemble it, and try to clean it out.

I don't know what else would work.

 

Oh yes, and the car DOES have ABS.
Not sure how that changes things, though.

 

Depending on the type of ABS system, you either purge as if it was an old
school type or use a scan tool to cycle the ABS. My lw300 uses a straight
through flow ABS and can be bleed without any fancy tools. Other types have
a small reservioir within the ABS module (pump and solenoids) that require
it to be cycled in order to bleed out all old fluid and air.


Oh yes, and the car DOES have ABS.
Not sure how that changes things, though.