The brake warning light appears and disappears randomly, usually once care is started stays on then after driving a little disappears?
only to come back randomly or at start up? faulty sensor?
Brake fluid line appears fine no leaks not high or low?
Thanks.

 

Welcome to the forum

You might check your brake light sensor. It may be dirty or not connected well? .
Also do a visual check for brake fluid leaks around the caliper hose. I realize that you did check you brake fluid revisor.

 

Thanks for the reply,
Yeah, did a pretty good visual check ( no leaks) ,
I did clean the sensor connector to the brake fluid reservoir?
don't know where the other sensors are? for that warning light?
I've heard that some sensor start becoming faulty after 10 yrs or so?

 

If it's triggering a light you may be able to catch it with a scanner when it happens. May be a bit out of left field, but if the fault is showing up at or around idling, it may be vacuum related.

There can be exceptions, but if the issue is a sensor it *should* throw a code. Any driveability issues?
I think uh.. ABS sensor rings (toothy looking gears tucked up against the backside of the wheel hub on the cv shafts) are sensitive to corrosion. Rust can build up and cause breakage/misalignment. That doesnt really match with your intermittent fault, but it's part of the system and worth a look-see considering ease of access. Dealt with them on an Escape hybrid, but can't recall symptoms.

 

Not always or necessarily!
In fact, this is a test question with becoming a Certified Auto technician. LOL
It may not throw a code, nor would it necessarily be in pending codes because when the light appears the code may not be generated by the ECU because there is a process to confirm an issue. If the issues is resolved the ECU will neither store nor will there be a DTC. At best you might see a DTC that is a generic code none directed caused by anomalous conditions. These type of DCT's only make the technician aware that there may be a problem and a systematic check of basically everything needs to be done. The good news is the more skilled and experienced the Technician in looking for them the faster a problem can be found and resolved.

 

You uh.. want op to just go to a mechanic?..

 

I didn't suggest that or word it it in anyway. However, when it comes to brakes IMHO if any DIY is asking on a forum and because it may be a safety concern, if they do not know how to properly diagnosis a problem then absolutely, they should at least get the vehicle looked at and the possible service needed to resolve the problem by a quality and perhaps better ones that have an ASE sign service shop. At that point they (DIY) can decide if they have the required tools and equipment and are capable of performing the repair or service!
And besides if I had it would be with a Certified Automotive Technician and not a mechanic.
Since 1995 when OBDII and CANbus ECU,PCM,TCM etc. now most all common (old school) auto mechanics became unfamiliar and not trained with the proper diagnostic problem solving required to work on many vehicles.

ASE

 

The end of your last post had me thinking you just wanted 'em to go to a shop. Apologies for my assertion there.

 

no not really .. but I did think that getting advise from a service shop may be in his better interest?

When at times on threads I end my response with ASE it is signing that is what I am.
I have been an ASE Master Technician for over 30 years and I am current. Testing to keep current certification is required every few years.

As for your responses on this forum, I find that your advice in various threads helping members is very good. Part of why I seldom participate in those threads that you have already recommended services.? And it seems you have a good amount of practical experience with a couple model Mazda's!

 

Brakes are critical for safety. IMHO Don't take DIY chances with your safety.
1. Check Corrosion, Wiring - I suggest checking the sensors / ABS sensor rings on each hub for corrosion, wiring, etc.
2. If interested in buying your own ODB2 Scan Code Reader, here is a link to Scotty Kilmer's ODB2 Scanners Readers. Pricing: The list starts at less than US$50 and goes up from there. Features described along with pricing .
https://carkiller.com/scottykilmer/postid/226842/