Bleeding brake lines on gm with ABS

[diehardbiker]

Im speaking in plain english. When the magnet sense it then it send signals which is "on" or 1 if it does not sense anything then it sense "off" or 0 When the wheel turns it goes back and forth like in wave. If the wheel gets locked, then it is flat line that is when control module realize that the brake is being locked up.
Of course, magnetic can cause voltage. The voltage is generated by magnetic field

And no I am not confused with digital and that is exact how digital works. Really no different, same thing how computer runs.

And do you have any idea what AC means? It is alternating current which in other word it changes from positive to negative constantly and that is called alternator opposing to DC which is Direct courrent and it has continus positive and continous negative. The concept is there.

No,AC voltage signals does not sense 0 and 1. You must confused with digital signals.


You should read the link that you post here.



Just use DMM and set to AC then connect to ABS's sensors and move wheel then you will see 0.1 VAC to 9 VAC depend on the speed and depend on the brand. It was not hard to do it.

Or use scope lab and make sure ABS's teeth (I forget what it calls) are okay.

 

[diehardbiker]

Exactly, I am just explaining in basic where generally everyone could at least understand.

Actually, on a very basic level, 1 and 0 represent charge or no charge I believe, but I could be wrong. On storage, yes, numeric value is used.

 

[deafsmogtech]

I don't have the answer on how to bleed with that GM ABS system, but yes there is sensor, where? If it is 2 wheel then there is two sensors and it is locate near the wheel. I forgot what it is called, that has magnetic field with wheel that looks like a gear but it is not. Intended to sense 0 and 1 when the wheel rotates, it sends out continue 0 and 1 which tells the ABS module that the wheel is rotating. In the event of brake being locked, it will stay either 0 or 1 while other wheel continue to send 0 and 1 continue ABS module would pump the brake fluid at the wheel where it continue either 0 or 1. For 4 wheel, it got 4 sensors, one at each wheel.

Damn I forgot what it called, and I had to fix the other day with stupid S-10 that got stuck. Found out that the magnetic sensor and the gear like teeth got no tolerance between. There should be limited tolerance (Hair thin) tolerance between the magnetic sensor and the gear like wheel. GM mechanic couldn't find the problem where I found on my own with help of my friend that knows this stuff.

Found it, I solved the problem because there was no air gap so I just pry it a bit, not much to create air gap and it worked.

To better understand how ABS sensor works. Here is the link

Brake & Front End: The Complete Undercar Service Magazine

You post and talk is exact as my post #31. If you wonder why I mentioned 3 wheel speed sensors? Domestic SUVs/ Light trucks use 3 wheel speed sensors: 2 sensors in the front where the sensor is mounted in the knuckle or in hub bearing assy, AND one sensor is mounted in the middle of the rear axle housing where the sensor senses the pinion gear ring.
Yes, they use 5 voltage reference input from computer and computer will read 0.0 to 1.0 AC voltage output from the wheel speed sensor.

 

[The Highlander]

Im speaking in plain english. When the magnet sense it then it send signals which is "on" or 1 if it does not sense anything then it sense "off" or 0 When the wheel turns it goes back and forth like in wave. If the wheel gets locked, then it is flat line that is when control module realize that the brake is being locked up.
Of course, magnetic can cause voltage. The voltage is generated by magnetic field

And no I am not confused with digital and that is exact how digital works. Really no different, same thing how computer runs.

And do you have any idea what AC means? It is alternating current which in other word it changes from positive to negative constantly and that is called alternator opposing to DC which is Direct courrent and it has continus positive and continous negative. The concept is there.

Umm No. You are funny. I suggest you google and prove me a link about AC use 0 and 1 signal. You won't admit that you are confused then. Learn how to check your spelling before you submit here. It's Direct Current, Not Direct courrent.

What does you think that I know about AC,DC, Ω, A, and mA mean? :roll:

Don't bother to explain me about AC mean. I knew it when I was very young. Thanks to my father who electoral engineering.


Binary numeral system - Wikipedia, the free encyclopedia

Read it carefully and slow. It's DOES NOTHING with alternating current.

The binary numeral system, or base-2 number system, represents numeric values using two symbols: 0 and 1. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used internally by almost all modern computers.

Like I said it's use digital.

 

[The Highlander]

ESC/ESP still associates with ABS systems.

Yes, That's right. ESC is better than ABS system only. I don't believe that my mom's BMW from 2000 and it already have ESC!. Almost 12 years later, then all vehicles must have ESC.

 

[deafsmogtech]

No,AC voltage signals does not sense 0 and 1. You must confused with digital signals.


You should read the link that you post here.



Just use DMM and set to AC then connect to ABS's sensors and move wheel then you will see 0.1 VAC to 9 VAC depend on the speed and depend on the brand. It was not hard to do it.

Or use scope lab and make sure ABS's teeth (I forget what it calls) are okay.

You correct and diehardbike correct too. I use my Fluke 98 II scopemeter to check waveforms (digital signals). DVOM? I use it for quick check like voltage present. Not good to test AC voltage, Scopemeter is the best way to check the AC voltage.
My mechanics in the past years, asked me why the ABS light come on after brake jobs, then I know they did damaged to the harness or sensor because they didn't realized the sensors or wires. I grab my scan tool to check the wheel speeds in live data while driving, found 0 mph on LF and other still display same 15 or more mph on the road test. Came back to the shop, told my mechanic to replace new WSS, he act like bitch, learn a lesson.

 

[diehardbiker]

Im not going to argue with you. I happen to type fast and accidentally misspelled. I am not saying your wrong but both of us are right anyway. The more 0 and 1 as if on and off in shorter time, the increasing voltage it can cause. They are both relativity and I am here just to give layman term how it sense in each sensor works. Whether it is by voltage or number of o and 1 in one second span. Both will have same result as far as I know.

BTW, I have certificate with Electrical and yes I understand how it works. So again, I am not saying your wrong on this one.

BTW, whats up with omega as Ohms, Milli amperes and amperes

Umm No. You are funny. I suggest you google and prove me a link about AC use 0 and 1 signal. You won't admit that you are confused then. Learn how to check your spelling before you submit here. It's Direct Current, Not Direct courrent.

What does you think that I know about AC,DC, Ω, A, and mA mean? :roll:

Don't bother to explain me about AC mean. I knew it when I was very young. Thanks to my father who electoral engineering.




Binary numeral system - Wikipedia, the free encyclopedia

Read it carefully and slow. It's DOES NOTHING with alternating current.



Like I said it's use digital.

 

[diehardbiker]

Here is link and you will find north and south there that is another way of saying 0 and 1

Hall Effect Sensors - Zero Speed Sensors - Quadrature Sensor

SPECTEC's magnetic Hall effect speed sensors are designed to switch in the presence of a magnetic field of 50 Gauss minimum. Magnetic Hall effect sensors meet a wide array of applications due to its ability to detect the difference in a magnet's north or south pole disposition. Both uni-polar (activated by either north or south pole magnets) and bi-polar (alternating north-south pole activation) are offered. In addition, an omni-polar model (HO type) is available which responds equally to a north or south pole field and converts it to a digital pulse.

 

[The Highlander]

certificate with Electrical? That's it? That's explained everything and it don't mean you know about automotive electrical. Just take class about Engine Performance and you will understand MORE than just electrical.


It's calls Hall effect sensor and yes, it's use digital which you talked about 0 and 1.

Hall effect sensor - Wikipedia, the free encyclopedia

Frequently, a Hall sensor is combined with circuitry that allows the device to act in a digital (on/off) mode, and may be called a switch in this configuration.

They are used in brushless DC electric motors to detect the position of the permanent magnet.

That's right. It's use digital and DC. There is no such AC at all.


I can't help but btw I have certificate with Electrical I,II, Engine Performance I,II, III, AAS degree for automotive technology and another AAS degree for Diesel.

Plan take one more class for CDL.


BUT you was right that hall-effect use binary.

 

[diehardbiker]

Cool
Btw no one is 100% expert this includes u and me and everyone else.

certificate with Electrical? That's it? That's explained everything and it don't mean you know about automotive electrical. Just take class about Engine Performance and you will understand MORE than just electrical.


It's calls Hall effect sensor and yes, it's use digital which you talked about 0 and 1.

Hall effect sensor - Wikipedia, the free encyclopedia





That's right. It's use digital and DC. There is no such AC at all.


I can't help but btw I have certificate with Electrical I,II, Engine Performance I,II, III, AAS degree for automotive technology and another AAS degree for Diesel.

Plan take one more class for CDL.


BUT you was right that hall-effect use binary.

 

[Jiro]

I see.... same ole' power-tripping quibbling habit...

 

[radioman]

Did you use 2 tubes like clear tubes or black vacuum hoses to attaching the ports (use nipple to male threaded adapters) while bleeding on the bench test? Did you rout the tubes from the ports to the bowl (reservoir)? The ends of the tubes must submerge in the fluid (inside the bowl) to prevent the air draw back as you can see bubbles while slowly bleeding. The fluid in bowl should be full while stroke the M/C. If bubbles disappear then plug the ends with penicls, remove from the vise and reinstall in the car and remove one adapter from port and quick install line to the port, finger tight it, do again in other adapter. Lightly tight flare nuts check fluid again, , make sure its full before you pump the pedal. Pump very slowly and depress, wait about 10 seconds, do again in few strokes. Tight front flare nut, leave loose rear flare nut, do pump again in few strokes. Last stroke press pedal you or have someone to hold the pedal down the floor then tight the rear flare nut and release pedal, loose the front flare nut, do repeat...

the proportioning valves are located at the sides of the ABS box, just below of the 3 metal hydraulic tubes (count 3 flare nuts) I think. If you see black cap on the side then pry it with small driverscrew, there you go

Uhhh - no not exactly -- more of redneck way. LOL. I think I'll go ahead and get parts needed for bench bleed the way you suggested.
As for the black caps on side of abs block, there are two. one in front and one in back. I loosen one of them with tube connected and no fluid came out after 5 mins messing with it.
FYI- I added pic of exact abs block I have for reference.

Plan take one more class for CDL.

I know we are going off topic- but have you joined deaf truckers united on facebook. It a bunch of deafs/HH who either have CDL's or wannabes in process of getting one. Basically this group formed because of the dumb hearing test part of CDL.

 

[deafsmogtech]

Uhhh - no not exactly -- more of redneck way. LOL. I think I'll go ahead and get parts needed for bench bleed the way you suggested.
As for the black caps on side of abs block, there are two. one in front and one in back. I loosen one of them with tube connected and no fluid came out after 5 mins messing with it.
FYI- I added pic of exact abs block I have for reference.



I know we are going off topic- but have you joined deaf truckers united on facebook. It a bunch of deafs/HH who either have CDL's or wannabes in process of getting one. Basically this group formed because of the dumb hearing test part of CDL.

Ok, you need to depress proportion valves, locate number 12 in pic. Pm u soon. I work on the cars rite now.

 

[deafsmogtech]

Yes, That's right. ESC is better than ABS system only. I don't believe that my mom's BMW from 2000 and it already have ESC!. Almost 12 years later, then all vehicles must have ESC.

No, ESC, ESP or TC is for traction/skip controls. ABS is for brake controls. Both still use wheel speed sensors.

 

[deafsmogtech]

I see.... same ole' power-tripping quibbling habit...

U funny

 

[deafsmogtech]

The hall effect devices such as crank/cam sensors, wheel speed sensor or vehicle speed sensor, that get DC voltage input from computer, hall effect sensors send AC voltage output to the computer. I know u guys are confused with AC/DC. They can be measure in millivolts (mv) and resistance (OHM) with DVOM and scope meter. My question is If the hall effect sensor increase high frequency, what speed is? High speed? Low speed? Answer me.

 

[diehardbiker]

The higher frequency the faster it gets and that is from my understanding. CPS is other sensor crankshaft positioning sensor.

The hall effect devices such as crank/cam sensors, wheel speed sensor or vehicle speed sensor, that get DC voltage input from computer, hall effect sensors send AC voltage output to the computer. I know u guys are confused with AC/DC. They can be measure in millivolts (mv) and resistance (OHM) with DVOM and scope meter. My question is If the hall effect sensor increase high frequency, what speed is? High speed? Low speed? Answer me.

 

[deafsmogtech]

The higher frequency the faster it gets and that is from my understanding. CPS is other sensor crankshaft positioning sensor.

No, high speed such as engine rev, the frequency will be low, mean AC voltage is low. Slow speed cause high frequency cuz of low counts on the teeth where the hall effect sensor senses, then convert to high AC voltages like volts goes drop to negative sides and goes up to positive sides like sine waves. That's how the ABS computer can see high frequency (slow wheel rotation) same as if any wheel get lock up than other the wheels then computer will dump more hydraulic to the brakes (unlocked up wheels) to maintain the brake balance. Computer will not read very low frequency well.
I hooked up my Fluke 98 II scopemeter to check the waveform in crankshaft sensor, with high engine RPM, the scopemeter show thin waveforms, can't catch it cuz of low frequency but you have to increase more millivolts in scope screen to get clean waveform picture.

 

[The Highlander]

No, high speed such as engine rev, the frequency will be low, mean AC voltage is low. Slow speed cause high frequency cuz of low counts on the teeth where the hall effect sensor senses, then convert to high AC voltages like volts goes drop to negative sides and goes up to positive sides like sine waves. That's how the ABS computer can see high frequency (slow wheel rotation) same as if any wheel get lock up than other the wheels then computer will dump more hydraulic to the brakes (unlocked up wheels) to maintain the brake balance. Computer will not read very low frequency well.
I hooked up my Fluke 98 II scopemeter to check the waveform in crankshaft sensor, with high engine RPM, the scopemeter show thin waveforms, can't catch it cuz of low frequency but you have to increase more millivolts in scope screen to get clean waveform picture.

That's what I thought so.


PicoScope high-resolution oscilloscopes for automotive diagnostics and fault finding

I really want one and I must buy it when I have money.

 

[radioman]

This is just an update on my fix. I finally bled my ABS brakes. It was a long frustrating journey that I wish it was published on web or I wish I found some sort of a link. I was able to glean a few facts after many google searches.

1. ABS modules that has kelsey hayes modules late 90's to early 2000's are PIB to bleed if drained completely from MC.
2. you need to get a small 1 gallon weed sprayer
3. you will need to bleed at least twice when you follow my steps.
4. we need to fire or shoot the SOB! GM CEO that approved the design that the engineers came up with that required the dang tech2 BIDIRECTIONAL scan tool.
5. you need a couple beers or stiff drinks on hand

steps:
1.after replacing the lines, do not connect the line to the ABS module just yet.
2.bench bleed the MC
3. take the weed sprayer and remove the spray wand and set aside if you need it for weeds( we dont need it for the brake bleeding). add fresh fluid in container about 2-4 ozs to cover the pickup. connect hose to the new line. Give the weed sprayer a few pumps. 4-6 times is sufficient since it will build up pressure up to 10-15 lbs and its more then enough. open the bleeder from calipers furthest away from MC on line you replace. wait for fluid to come out in steady stream. close and repeat other side after checking level in weed sprayer tank.
4. connect the line back to ABS module and attempt to bleed all 4 sides. If you see the fluid is NOT coming out from a particular line, you will need to bleed the ABS module and if you dont have tech2 scan tool to open the valves on kelsey haynes module, then you need to take vehicle on a slippery surface like grass, pavement with lots of stones or stone driveway and slam on brakes while moving above 20 mph and make ABS kick in several times. This will help to purge the air from ABS module and you can rebleed the darn brakes again.

You should have a firm pedal by now.

If you attempt to bleed the brakes normally with kelsey haynes module without expensive equipment- you will just be frustrated as you cant get fluid to come out as the ABS valves keeps slamming shut due to nature of air is VERY compressible in the new line. The trick basically is to precharge the new line with fluid from end to end BEFORE making the connections.