What can cause the brake warning light to come on if my pads and shoes are all good and my brake fluid isn't low?

Under fairly hard braking, and even under hard acceleration, the brake warning light flickers on, getting brighter the harder I stop, just as if I was low on fluid or my pads were totally shot.

Zulued and I just swapped in a new tranny, clutch, flywheel, and axles on saturday. We didn't touch any of the brake system, but it's been doing it since. It's a 91 CRX DX with and LS swap.

 

MC cap might be bad, possible

Fluid to low, brake pads worn out, can all cause the light to come one

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX Toad &raquo;</TD></TR><TR><TD CLASS="quote">MC cap might be bad, possible

Fluid to low, brake pads worn out, can all cause the light to come one</TD></TR></TABLE>

fluid level and brake pads are ruled out. I actually wondered about the mc cap though. can that little bobber thing go bad? Anyone have a cap they feel like parting with?

 

Ok, so I'm not sure if it's coming on due to hard acceleration, or high rpms, but it started to come on today when I was winding out third gear. It started up around 4500-5000 rpms, and disappeared as soon as I shifted.

A hard stop will make it come on more easily, but only under relatively hard stopping.

 

Maybe the fluid is being slushed around enough to drop the float really quickly.

 

bumpin this up for any more info someone wants to add..i have the same problem at the moment..i do remember someone mentioning before that their MC went bad and it happened quite suddenly and then had no brakes shortly there after..i'm hoping this doesnt happen as my brake pads "seem" fine and the fluid also seems correct/filled(isnt there an e-brake handle"sensor" ?)damn old cars

 

Yea, there's an ebrake sensor that's under the center plastic right where the ebrake is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by buckethead36 &raquo;</TD></TR><TR><TD CLASS="quote">bumpin this up for any more info someone wants to add..i have the same problem at the moment..i do remember someone mentioning before that their MC went bad and it happened quite suddenly and then had no brakes shortly there after..i'm hoping this doesnt happen as my brake pads "seem" fine and the fluid also seems correct/filled(isnt there an e-brake handle"sensor" ?)damn old cars </TD></TR></TABLE>

the mc itself? or just the cap?

thanks for the input so far, guys.

 

so I unplugged the wires to the mc cap and beat on the rex a little bit yesterday and today. so far I can't get the light to come back on. looks like I'll be replacing the cap. (if anyone's got one they can get rid of, pm me)

 

Update:
So I disconnected the two wires to the cap, and for a couple days I couldn't get the light to come on. I thought I found the problem, but I guess not.

Just last night I was driving around, and I noticed that suddenly, when I coast in any gear above 2k rpms, without giving it any gas, the brake light again flickers on. Also, I noticed a slight squeek coming *maybe* from a back wheel, but I wasn't able to tell where it's coming from yet. Of course, what EF doesn't have a half dozen or more squeeks?? Might be related, might not.

 

help me out guys. brakes are important things to keep in proper working order.

 

OK, this thing's coming on more and more easily. When I accelerate, it starts coming on around 4500 or 5000 rpms and up. When I brake hard, it comes on too. When I'm coasting in gear above 2250 rpms or so, it comes on, but if I step on the gas it will go back out. It even comes on for a second when I shift (and therefore am not giving it any gas) until the rpms fall enough that the light goes out anyway. It almost *seems* as though it could be a vacuum problem, but I know that doesn't really make sense. Pedal still feels like it always did (so far).

What's involved in replacing a MC? I think I'm gonna try that if nobody has a better idea. I just *really* don't have money to be replacing things that aren't broke!!

 

the cause of my brake and an ignition problem was.........

the reverse sensor wire! duh! why didn't you guys think of that sooner?! LOL

the idiots that wired in my swap 3 years ago weren't exactly wiring experts, and this wasn't the first bad connection they've made, but when we were replacing the transmission, the wires got all twisted up because they were hard wired (no harness) for some dumb reason. Literally minutes before I was about to take my car and drop it off at the garage, Zulued remembered noticing the shitty wiring back when we swapped the tranny. I cut the wires as per his suggestion, my car started, took it for a drive and the brake light didn't come on, came back, and the key popped right out.

I'm almost kinda pissed at how simple, yet how completely ******* obscure the problem was! At least I don't owe a mechanic for countless hours of diagnostic time.