Resurrecting the mess that is the work van and it has an odd issue. 88 Club Wagon
The brake warning light comes on during bumps. The brake fluid is most definitely not low and the float in the master cylinder seems to be moving freely. The brakes are as good as theyve always been and I've done several panic stops to make sure. I have pushed the float down while it was sitting with the brake light on and it turned off the light but the float was in the same place both times.
Am I missing something stupid? I'm tired and used a jackhammer all day so stupid could be happening
In reply to Antihero (Forum Supporter) :
Dirty ground?
Whats up with your e-brake sensor switch?
When the parking brake pedal is depressed, that movement of the pedal triggers a switch to turn on the brake light.
If the spring holding up the pedal is sloppy then hitting a bump may allow the pedal to move enough to trigger the light.
Next time the light comes on, try using the top of your foot to move the parking brake pedal back into place. This might also require pulling the release handle at the same time.
I didn't think of the e brake, apparently I'm stupid tired lol
Pulling the release and pulling up on the ebrake have no effect.
Brakes still work well, if the light didn't flicker on I wouldn't suspect anything
Is it one of the warning lights that is supposed to identify a pressure difference between front and rear circuit - meaning you have a leak or loss of fluid on one end or the other?
Robbie (Forum Supporter) said:
Is it one of the warning lights that is supposed to identify a pressure difference between front and rear circuit - meaning you have a leak or loss of fluid on one end or the other?
I'm not sure, but I haven't lost fluid at all.
I'm trying to remember whether this is what I had with the '91 F250, and whether that's era-correct enough to be useful anyhow.
It... might... have had something to do with the road speed sensor at the diff? This was rear-only ABS.
It might also have been funkiness with the fluid level sender that you've already ruled out. It's been a while and I can't remember how much better my memory used to be.
I will assume the fluid level is full. Is it clean? Is it bubbly? Is the interior of the reservoir vessel dirty? Are there wires coming from the resvoir vessel? With a helper smack the top of the reservoir to see if the light comes on.
I think that it has a low fluid indicator that is either dirty, faulty or showing.
Antihero (Forum Supporter) said:I have pushed the float down while it was sitting with the brake light on and it turned off the light but the float was in the same place both times.
I was just rereading the original description and this is giving me trouble.
- What do you mean "sitting with the brake light on?" By the rest of the description, the light isn't on unless you're traversing bumps. Or does it stay on after a set of bumps and this is when you do the above?
- If you were sitting there with the brake trouble light on and the float was going to turn it off, I would expect you to pull it up, not push it down... Right? I mean, this shouldn't be it because the fluid's full, but "further floaty" shouldn't be turning the light on, and "pushing it lower" shouldn't turn it off...
Before I ramble further, would you mind clarifying that? I'm assuming I'm failing to pick up what you're putting down, but now I'm in left field.
Unplug each switch in sequence and see which one solves the problem. Level switch, park brake switch pressure differential switch. Which ever one makes it stop flashing is the one to chase.
In reply to Jesse Ransom :
I didn't explain it well, I was tired and barely there.
Once when I came to a complete stop, after a bigger bump, the light stayed on. I let it idle for a second to see if it would turn off and when it didn't I popped the hood to check and make sure I had fluid. I popped the reservior open to check the float and see if it stuck. It wasn't and I lightly pushed it to make sure. I put the cap back on and went to turn off the car. The brake warning light was now off. The only changes were me pushing the stupid little float down and opening the reservior.
The brake fluid is clean, no bubbles, the cap comes off easily, the level never drops and the brakes feel as good as they always have.
This van has been......not maintained well so there being little issues is by far not something I didn't expect
QuasiMofo (John Brown) said:
I will assume the fluid level is full. Is it clean? Is it bubbly? Is the interior of the reservoir vessel dirty? Are there wires coming from the resvoir vessel? With a helper smack the top of the reservoir to see if the light comes on.
I think that it has a low fluid indicator that is either dirty, faulty or showing.
Level is full, fluid is clean, no bubbles either. I'm leaning towards the low fluid float being a little screwed too. If the light wasn't on I wouldn't assume there was a problem with how the brakes are acting.
Smacking the reservior is a good idea, I'll do that
In reply to Streetwiseguy :
Good advice, I'm leaning towards it just being a sensor and not a problem but I like brakes that work so have to check everything
In reply to Jesse Ransom :
I think there's another specific warning light for the rear antilock, and I'm not even sure it has it now that I think about it, but that's something I didn't think of
That leaves me wondering about the contacts on the float or in some connection to that sensor.
Popping the float down caused motion, got it off the dead spot on the contacts, etc?
My 96 econoline has a vacuum sensor as well. If there are vacuum leaks it'll come on, or in my case when I press the brakes and vacuum in the system drops.
In reply to Jesse Ransom :
That's where I'm leaning, usually brake problems aren't subtle, I have fluid, brake pads and I'm stopping.
In reply to WillG80 :
The only time this doesn't happen is when I hit the brakes, which is even more weird
Is the float switch in this case a simple switch? Is there a connector?
Just wondering if you can diagnose by either unplugging it or jumpering it (Not sure which is "float low," open or closed contact). Obviously not as a fix, but if circumventing the float switch fixes the problem, it's the float switch.
