Brake Light comes on when hard braking

[MP5Navy]

I've got 65,000kms on my ride and have not done a brake job yet - cause I don't need to yet (pad wise). I'm not too low on fluid but when I brake hard my brake light comes on in the dash - it's been happening for 2 weeks.

Anyone else with this problem?
I probably just need to top up my fluids - what do I use?

[RiceWagon]

You might want to check your pads. My car was doing the same thing after the winter, turned out to be a slight loss of brake fluid and my pads were wearing pretty thin. When the brakes were applied hard the piston in the caliper had to pushout further (using more fluid) to make sure the almost wornout pad was making proper contact with the rotor. Thus the brake light would come on since apparently our system can notice as little as a half/ounce of fluid being low. I added a little bit of fluid to my car to get it by till I wanted to actually change the pads... worked like a charm.

Mark

[superdave]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (RiceWagon @ June 13 2003,09:41)</td></tr><tr><td id="QUOTE">You might want to check your pads. My car was doing the same thing after the winter, turned out to be a slight loss of brake fluid and my pads were wearing pretty thin. When the brakes were applied hard the piston in the caliper had to pushout further (using more fluid) to make sure the almost wornout pad was making proper contact with the rotor. Thus the brake light would come on since apparently our system can notice as little as a half/ounce of fluid being low. I added a little bit of fluid to my car to get it by till I wanted to actually change the pads... worked like a charm.

Mark[/QUOTE]<span id='postcolor'>
In a properly working system the pistons will stay in contact with the pads at all time. The only way the piston will recess in very far in order for it to have to push out a long way again under braking, is if the rotors are warped.

Dave: Is it possible your rotors are warped? This would cause relatively large fluctuation in fluid level.

[MP5Navy]

No I'm sure my rotor are perfect - the wear is even and the pedal feel is linear.

I'll top up on my brake fluid - but what Dave said is right about the pistons.

What DOT spec brake fluid do I use? I'm guessing 3?

[Logan]

I haven't checked through my manual to see if it's in there, but it might be.

[rowan]

DOT 3 is what's in there from the factory.

[Action Jackson]

Since the clutch and brake system share the same fluids [at least I believe so] and the same resorvoir, any recommendations?

Redline comes to mind but that's usually for brake fluid.

[superdave]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Action Jackson @ June 13 2003,8:33)</td></tr><tr><td id="QUOTE">Since the clutch and brake system share the same fluids [at least I believe so] and the same resorvoir, any recommendations?

Redline comes to mind but that's usually for brake fluid.[/QUOTE]<span id='postcolor'>
Redline comes to mind for brake fluid? I dunno I usually think gear box fluid.. anywho ask Rowan and Simon about Motul. I think they are both happy with the clutch/brake and gear box fluid. http://msg.toprotege.com/iB_html/non-cgi/emoticons/thumbs-up.gif

[Action Jackson]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (superdave @ June 14 2003,02:23)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Action Jackson @ June 13 2003,8:33)</td></tr><tr><td id="QUOTE">Since the clutch and brake system share the same fluids [at least I believe so] and the same resorvoir, any recommendations?

Redline comes to mind but that's usually for brake fluid.[/QUOTE]<span id='postcolor'>
Redline comes to mind for brake fluid? I dunno I usually think gear box fluid.. anywho ask Rowan and Simon about Motul. I think they are both happy with the clutch/brake and gear box fluid.  http://msg.toprotege.com/iB_html/non-cgi/emoticons/thumbs-up.gif[/QUOTE]<span id='postcolor'>
Doh!

Motul, that was it!