Brake Light Intermittently Coming On

[dnellans]

So as the subject line says the brake light on my '92 XL has started coming on recently intermittently. It happens only when I am braking and then goes off when i let off the brake. However it doesn't always happen, just sometimes and I can't narrow down why or when yet. I looked and I don't need to add brake fluid or anything.

Anyone know what sensors can trigger the brake light? The braking is positive and there hasn't been any change since it started going on so I'm at a bit of a loss.

any thoughts would be much appriciated
-d

 

[Pheonixx77]

well mine came on intermittently but never whan i was braking, it came on when i started the truck (assuming you mean the abs light) it was really difficult to get it to go off, sometimes shutting off the truck and startng agan made it go off. but when i bled the ENTIRE brake system it went off and has stayed off for a few weeks now. maybe you need to bleed the brakes?

 

[dnellans]

a good thought... its about time to do my front pads i think so maybe i'll bleed them a bit when do the pads and see what happens. and yes, i meant the abs brake like (thanks for the clarification) maybe i should try locking the brakes up and see if abs is actually working??

-d

 

[Pheonixx77]

f you are gong to bleed the brakes do them all, not much time involved maybe an hour and a half. i used valvoline syn power. its a synthetic and its clear so i knew when all old fluid is out. i used two of the big bottles to do this, the rear pass side was the longest and after that it bled out quicker. but i would suggest getting ALL the old fluid out. thats mainly why i bought the valvoline stuff, cause it's clear.

 

[dogfriend]

A problem with the ABS system can trigger the brake warning light. I would try bleeding the system first as suggested. If that doesn't help, then it could be a problem with the ABS. I had the same problem with my 89 Ranger with rear only ABS. It could be air in the system, or another problem.

 

[dnellans]

i headed down to autozone and got two of the larger (quart?) bottles of valvoline at your recommendation... figuring that you're right and i might as well do them all if i'm doing some of them since i think the fuild is still the original from over 10 years ago

i haven't bled brakes in probobly 5 or 6 years now, is the procedure still the same?

find the longest line, passenger's rear as you say, open the reserve cap and the brake bleeder in question, and have somone keep the reserve full of new fluid while i pump the brakes until new fluid comes out the bleeder?

just want to make sure i've still got that right before doing it.

thanks again
-d

 

[dogfriend]

The procedure is pretty much the same - except if you have 4 Wheel ABS - then you may need a special tool to bleed any air in the HCU. Usually you would only have a problem with this if you took some lines off of the HCU or one of the calipers. I have 4 wheel ABS, and I was able to bleed the system normally.

Here is a link with the basics:

Brake Bleeding Procedure

 

[MyExpWork]

My 91 does the same thing. More under heavy brakeing. All it means is that the fluid in the resivoir is moving foward due to the G's when braking. Add fluid and it will go away.

For me, when it starts doing this, it is time for my annual set of rotors and pads. Thicker rotors move fluid back to the resivoir and the light never comes on...Until 11-12 months later.

Brian