Brake light coming on when pressing the pedal.

[Mark Phillips]

Hey guys, so the brakes are new, master cylinder, booster , propositional valve is new. Why would the light come on when you mash the break pedal. Brakes seem real good.

 

[GoldenOne7710]

I assume you mean the brake indicator on the dash? How's the fluid level in the master cylinder?

 

[Mark Phillips]

Fluid is good

 

[suds788]

Just a thought - try rebleeding your system again might have air causing the proportioning valve not to position right (or a bad proportioning valve - not sliding like it should). If the brakes are working good light is probably on because of the valve position(uneven pressure between front & back brakes). Might also check that the wire going to the valve is on good. Hope this helps.

 

[Twisted_Metal]

The "brake" indicator light won't illuminate if the wire isn't connected.
The switch has made ground in the circuit at either the proportioning valve or the e-brake switch when the light is on.

I'm betting there's still a couple of bubbles in a brake line somewhere.
It takes VERY LITTLE air to cause the center of the proportioning valve (or combination valve) to move enough to ground the switch and illuminate the light.

If the light is going off when you aren't hitting the brakes... the center is moving back to where it's supposed to be.

 

[Mark Phillips]

The light comes on when applying the brakes only, doesn’t come on at all when it’s just sitting there running or driving until you apply the pressure. It was a new valve but could be bad.

 

[suds788]

More than likely air as we said - won't hurt to bleed and see if it fixes it. Like Twisted said if light goes out when you release brake the valve is repositioning correctly.

 

[Mark Phillips]

Thanks guys, I’ll bleed it some more to see if that takes care of the issue.