Master Caution Warning question
07-12-2002, 05:06 AM
#1
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Master Caution Warning question
Is there an order of precedence?
If a master brake warning with low pressure or pressure imbalance note is present can other warnings of greater, equal, or lesser importance also display at the same time?
Do you have to clear the initial Brake Warning before other gigs reveal themselves on the Master warn?.
My problem is: Prior to Sito I had a Master Caution, Brake warn -Pressure- indication.
I mic.'d the rotors,(ok), cleaned everything, roughed the rotors, checked and cleaned the piston boots, scuffed the new pads, changed the sensors, bled the system -several times-, and did the engine on/off master cylinder pump and hold bleed down tests.
Brake warn went out after battery disconnect and recharge. Came on again on the trek to shARKANSAS.
Dave, Jay, or Herr Wilson -my new Guru- recommended a continuity check on the new sensors which I have done twice(ok). Can't clear the gig.
Brakes work fine, no glazing, pulling, or leaks. Did the battery disconect, pulled the master cylinder switch/sensor leads and cleaned. The warning is still indicated. How do I jump the Brake sensor leads -no cutting- to see if that will clear the Caution board?
TIA
John S. & Pattycakes
<img src="confused.gif" border="0">
If a master brake warning with low pressure or pressure imbalance note is present can other warnings of greater, equal, or lesser importance also display at the same time?
Do you have to clear the initial Brake Warning before other gigs reveal themselves on the Master warn?.
My problem is: Prior to Sito I had a Master Caution, Brake warn -Pressure- indication.
I mic.'d the rotors,(ok), cleaned everything, roughed the rotors, checked and cleaned the piston boots, scuffed the new pads, changed the sensors, bled the system -several times-, and did the engine on/off master cylinder pump and hold bleed down tests.
Brake warn went out after battery disconnect and recharge. Came on again on the trek to shARKANSAS.
Dave, Jay, or Herr Wilson -my new Guru- recommended a continuity check on the new sensors which I have done twice(ok). Can't clear the gig.
Brakes work fine, no glazing, pulling, or leaks. Did the battery disconect, pulled the master cylinder switch/sensor leads and cleaned. The warning is still indicated. How do I jump the Brake sensor leads -no cutting- to see if that will clear the Caution board?
TIA
John S. & Pattycakes
<img src="confused.gif" border="0">
07-12-2002, 10:40 AM
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John - One way to test the master brake switches would be to take a Ohm meter and check continuity acress the terminals on the switch. There are 3 terminals on the bottom of each switch once you remove the boot. Terminal 81 which shows a black/red wire attached to it (according to my wiring diagram) is where one of your Ohm meter leads (we'll call it Ohm meter lead #1) will go. You should be able measure zero Ohms to one of the other 2 terminals using Ohm meter lead #2. You will need someone else to step on the brake pedal and your Ohm meter should show open circuit across the terminals that previously showed a short. If you move Ohm meter lead #2 to the 3rd terminal with the brake pedal still depressed you should see a short. Check both switches this way. It may be an intermittent failure so you may have to pump the brakes several times to get it to fail. Good luck!
07-12-2002, 11:04 AM
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John-
Just to clear things up a bit for a dolt such as myself - are you getting the brake pad warning light, or the Brake Fluid/Pressure Lo light?
I seem to remember that at SITO your problem was the Brake Pads - but I'm reading it's the Brake Fluid/Pressure now?
Geez - I realy need a better mind in the mornings.
Just to clear things up a bit for a dolt such as myself - are you getting the brake pad warning light, or the Brake Fluid/Pressure Lo light?
I seem to remember that at SITO your problem was the Brake Pads - but I'm reading it's the Brake Fluid/Pressure now?
Geez - I realy need a better mind in the mornings.
07-14-2002, 03:27 PM
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Jay,
My response went to Never-Neverland, sorry!
It is the brake pressure warning.
Since the 928 has a dual diagonal brake map I went thru and:
1. Mic'd the rotors. OK
2. Mic'd the Pads. OK OEM's out of Australia purchased thru 928 INT'L.
3. Checked for release on each wheel after letting off the brakes - did this cold and hot. OK.
4. Dragged out the mutiMeter and went thru the sensors , yet again. OK
5.Did the hold pressure checks for the master cylinder - engine on and engine off.OK
6.Bled the brakes - looking for contaminants this time - for the 4th time. OK -Like new/clear.
It's gotta be electrical...somewhere.
I'm almost hoping it's related to that miserable bulb/lamp control switch. Max, a real trooper, is helping with the electrical schematics which I should have sometime next week. Unfortunately one of our inspectors seriously flubbed a highway signeage, road marking, delineator contract in another county so for the next week I'm on the road from 6am to 8pm stamping out fires.
As usual, any help appreciated.
TIA
John S and Pattycakes.
BTW 2 items. 1.) I just noticed the price tag on the Glycol you so casually supplied to me in shARKANSAS. U will be compensated - was it one or two jugs? 2.) Are there any other flicks forthcoming from SITO? I know Dave took a number with his 35mm. I think the low angle high intensity 'SUN' shots defeated most attempts at getting good shots. Next time evening shots at the Crescent for that rosy glow on the paint keeping in mind that those with lighter colored cars will appear different than in real life but they WILL LOOK GOOD! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
My response went to Never-Neverland, sorry!
It is the brake pressure warning.
Since the 928 has a dual diagonal brake map I went thru and:
1. Mic'd the rotors. OK
2. Mic'd the Pads. OK OEM's out of Australia purchased thru 928 INT'L.
3. Checked for release on each wheel after letting off the brakes - did this cold and hot. OK.
4. Dragged out the mutiMeter and went thru the sensors , yet again. OK
5.Did the hold pressure checks for the master cylinder - engine on and engine off.OK
6.Bled the brakes - looking for contaminants this time - for the 4th time. OK -Like new/clear.
It's gotta be electrical...somewhere.
I'm almost hoping it's related to that miserable bulb/lamp control switch. Max, a real trooper, is helping with the electrical schematics which I should have sometime next week. Unfortunately one of our inspectors seriously flubbed a highway signeage, road marking, delineator contract in another county so for the next week I'm on the road from 6am to 8pm stamping out fires.
As usual, any help appreciated.
TIA
John S and Pattycakes.
BTW 2 items. 1.) I just noticed the price tag on the Glycol you so casually supplied to me in shARKANSAS. U will be compensated - was it one or two jugs? 2.) Are there any other flicks forthcoming from SITO? I know Dave took a number with his 35mm. I think the low angle high intensity 'SUN' shots defeated most attempts at getting good shots. Next time evening shots at the Crescent for that rosy glow on the paint keeping in mind that those with lighter colored cars will appear different than in real life but they WILL LOOK GOOD! <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
