Karl Townsend wrote:
I bought a brake controller that uses a sensor in the brake line. Today, I
took the brake line apart at the master cylinder, installed the "T" and
sensor. Had my better half pump the brakes while I bled. No big deal, I
thought.

Well, as soon as I started the truck, the brake warning light came on. So I
had the better half pump the brakes while I bled a whole can through the
front wheels. No joy.

I called "the Kid". He said to get a vacuum device from bumper bumper for
only $20. Well, it was $50. But I got it and bled a can through each front
wheel. No sign of bubbles at all. Note: the sensor is on the front set on
the tandem brakes

Still no joy. I got a brake warning light. I just got ****ed and called it a
day. What do I do tomorrow?

Take the whole thing off?

Maybe post on the automotive newsgroup, and include you make & model of
truck?

Writing built in test code for just about any mechanical device is a
bitch and a half -- you've got this computer that is deaf and blind,
that's trying to deduce the health of some mechanical hardware without
being able to sniff or look for leaks, etc. False alarms are common,
even when the assembly _isn't_ broken.

So I'm not surprised that you confused the poor thing.

Either the amount that the pressure sensor moves makes the system look
leaky, or there's still a trapped bubble, or your brake controller's BIT
function remembers when it's _been_ broken and you need to go reset the
code.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com