Oppo I have the worries

"Flynorcal: pilot, offshore sailor, car racer and panty thief" (flynorcal)
03/30/2018 at 00:38 • Filed to: None

I’m at my hotel near Laguna Seca, where I intend to drive at high speed in about 10 hours and I would like to confidently do so without wondering how I’m going to slow back down.

A little less than two weeks ago I blew a new brake hose at Sonoma Raceway. I wrote a bit about it.

!!! UNKNOWN CONTENT TYPE !!!

So the car has new braided stainless lines all around. I’ve driven it maybe two hours with it feeling perfect. Then, on my way to the hotel, on the freeway, the light started intermittently coming on. I assumed there must be a leak. I pull off and nope. It’s full. No visible leaks.

I have new rotors, new pads all around, braided lines, new master cylinder, a DRM bias spring in said new MC (to put more power to the rear brakes), racing brake fluid, and brand new beautiful stainless lines.

I can get the light to stay on if I push the pedal down fully. Otherwise it sometimes comes in when I lift and it’ll stay on until I tap the pedal and it goes out.

If I get to speed and hit the pedal to stop as fast as I can... Works great. Just an idiot light.

The same light comes on for the emergency brake. I’ve checked it’s not partially on.

I have no idea how good the folks are who did the work.

I’ve changed just about everything. The brake fluid and braided lines will add a ton more pressure to the system. I suspect there’s a sensor complaining. Or a loose wire.

I’ve got no other guesses.

This is a 92 Corvette C4 LT1.

Oh and the wheels are from a C5 which fucks with the traction control if you forget to turn it off but those are different lights. As to the wiring if you go over a sharp crest in this car the interior lights flash.

Thanks in advance for any guesses of any kind.

DISCUSSION (8)

PS9 > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/30/2018 at 00:58

*Pfft. Slowing down? Screw that noise! Leave that pesky safety shit to the soccer moms and and minivan dads. The sand trap got it if you don’t. NEVER LIFT.

*(This advice is awful. Please do not follow it. Do not race the car if you’re not sure it can be stopped.)

Highlander-Datsuns are Forever > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/30/2018 at 01:05

Just cover the light with some black electrical tape. I guess I’d be more worried at Sonoma with it’s hard braking zone, if things start acting up then just pull off and call it a day. I recal that laguna seca scrubs lots of speed at the bottom of the corkscrew sooo.... don’t loose your brakes there.

jasmits > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/30/2018 at 01:10

Check the float in your brake fluid reservoir. In my 2nd gen 4Runner(so, very different vehicle but from the same time) the little plastic float that judges the level in the brake reservoir cracked and sunk to the bottom, so no matter what the brake light was on. I just unplugged it and checked it religiously.

But before it had fully cracked it must’ve had a little leak or something and was hovering somewhere in the middle because for a bit the light would come on intermittently which caused some worry to say the least.

Flynorcal: pilot, offshore sailor, car racer and panty thief > jasmits
03/30/2018 at 01:29

Brand new master cylinder makes that seem unlikely but hey — checking the goddamn wire isn’t loose to the recently replaced item — this is a very good lead. Thank you.

jasmits > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/30/2018 at 01:33

Oh right duh, the new master cylinder didn’t totally register I guess. But yeah, anything to help! Hope you figure it out and have a good day tomorrow.

Flynorcal: pilot, offshore sailor, car racer and panty thief > Highlander-Datsuns are Forever
03/30/2018 at 01:37

I’m using black mental tape over the light until something corroborates that there is an actual problem. You know your tracks so I can tell you my only real worry which is turn two into the hairpin after the straight. You lose so much time if you don’t keep it pegged over the blind little hill at turn one... But you have to see God briefly before nailing the brakes.

I’m pretty sure I’ll not be pushing my luck there ... or turn 11. I bet it has runoff but I can’t picture it in my mind.

sony1492 > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/30/2018 at 02:42

Nitpicking: SS lines don’t increase pressure, but they decrease pedal distance to a desired pressure. Getting water out of the fluid will also allow you to reach a higher pressure with less pedal movement. Your system will be more responsive but the pressures its capable of are the same.

Maybe the lights coming on because the sensor wires grounding out? Maybe check the connection and see if anythings pinched.

Flynorcal: pilot, offshore sailor, car racer and panty thief > sony1492
03/30/2018 at 03:10

I more meant the brake fluid. I think the original fluid from 1992 must have been in there were when I bought the car as it’d boil like a kettle not so much on the track but after, in the paddock, when it was all heat soak without cooling. I’d lose my brakes completely after sitting a few minutes but they’d cool off and work again.

That was my first step down this Rabbit Hole. Brakes are supposed to be easy I thought? Wasn’t that the general consensus?