Well I found out that the short answer is no - without the GM Scan Tool, you can't.

But there are ways around it. The ABS system used on '95 through early 2000's GM trucks is the Kelsey-Hayes EBC310. It has three sections - one each for the left- and right-front wheels, and a third for the rear axle. Each section is divided into an Isolation valve and a Dump-Valve/Low-Pressure Accumulator.

When bleeding the brakes the low-pressure accumulator is 'hidden' behind the dump-valve and can't be bled. The only way to flush the fluid and/or air from these areas is to cycle the ABS. The factory-approved method is to use the Tech 1 Scan Tool to command the computer to cycle the ABS.

But the "shade-tree" mechanic method is to drive down a gravel- or snow-covered road and jump on the brakes, which will cause the wheels to lock up and... cycle the ABS.

There's an obvious flaw in this procedure - one has to get the brakes working well enough to safely drive down said road. Plus, when the ABS cycles any air in the accumulators will be dumped into the lines. This may have a dramatic negative affect on your braking ability. Assuming all goes well and you were able to get all three circuits to activate (LF, RF and one of the rear wheels), then it's time to gingerly drive back home and bleed the rest of the air out of the system.

You can read more about bleeding ABS brakes here:

Brake & Front End Magazine, "Bleeding ABS Systems" by Bill Williams (July 2005)

 

Actron just came out with this ABS reader, it gives you a code and detailed description for $229. I bought one to go with my Auto X-Ray scanner, and those two things pretty much cover all bases. You are right though you still have to get the system reset in order to operate those valves, but the scanner is still a nice thing to have anyways. arty:

http://www.gmtruckclub.com/forum/attachment.php?attachmentid=2059&stc=1&d=1235879062

 

I'm interested in your review of that device.

One problem I had was trying to read the ABS and TCS codes on my wife's 2000 Pontiac Grand Prix. In theory, any ODBII scanner can read engine as well as transmission and brake codes (they're all in the OBDII specs and the codes are defined).

But in reality only the engine-codes (i.e. - emissions-related stuff) are mandated by law. So the manufacturers are free to chart their own course on the other stuff - and frequently do.

So with my wife's car we had to go to the dealer to get the codes. That, combined with the trouble-shooting in the service manual leads me to believe the ABS computer has failed. Still, I would rather have spent the $100 the dealership charged for diagnosing the problem on a scan-tool of my own.

 

Here is a little info on the Actron ABS Brakescan:

This affordable alternative for diagnosing brake problems displays ABS trouble codes and definitions on an easy to read backlit display. ABS Brakescan eliminates guesswork and helps identify the parts required for brake repair.
Systems diagnosed include wheel speed sensors, ABS solenoids, the brake control module, ABS pump motor, vehicle speed sensors and more.
This simple to use scan tool plugs into the vehicle's OBD II port and provides coverage for most OBD II domestic vehicles 1996 and newer (GM, FORD, and CHRYSLER). ABS Brakescan is updatable online, features an ABS code library, retains the most recent vehicle scan, and has intuitive help screens.

ABS Brakescan includes: CP9449 handset, detachable vehicle cable, a durable/soft carrying case, and a quick start manual. Optional battery power enables ABS Brakescan to save and view data when not connected to the vehicle.

I typed this directly from the introduction page of my booklet, I couldn't get it to down load. I am like you KirkW, even if I can't fix it I would still like to be able to diagnose it and sometimes actually be able to fix it. It is brand new to the market so there are still some bugs they need t work out, but I have already used mine twice and I have only had it a month. Hope this helps you out, and I know you won't regret the purchase.:great:

 

So, stupid me decides to replace the brake booster and master cylinder in a '99 Yukon and then try a conventional brake bleed sequence. After going through 5 bottles of brake fluid and only getting to the second wheel, I figure there must be a problem. When the brake pedal is depressed, I can hear bubbling sounds in the ABS modulator. It has 4 wheel ABS. I search and find that the only way to get air out is to use a GM scan tool through the dealer. However, I can't even do the conventional brake bleed because there are so many air bubbles in the lines.

I've seen workaround posted like the one above that talks about getting the ABS to be locked up on a gravel road as well as just turning on the ignition and bleeding that way. Can anyone confirm if either of these really works or if there is a better way? My problem is with air in the brake lines, taking the Yukon out to a gravel road isn't really feasibly with so much air still in the system.

Hoping someone can help so I can get this finished. Been without the car for going on 4 days and had no idea the job would be so difficult on the Yukon. Thanks!

 

Dave - you might just try using gravity to bleed the system. It's not fast, but will work. I have a friend who does auto work on the side, this is what he does. Just crack the bleeder, and let the fluid drain down, keep the reservoir full.

 

Dave - you might just try using gravity to bleed the system. It's not fast, but will work. I have a friend who does auto work on the side, this is what he does. Just crack the bleeder, and let the fluid drain down, keep the reservoir full.

I'm not 100% sure, but can't see how gravity bleeding would rid the ABS modulator of air. I think it needs some kind of pressure from actuating the internal valves or something like that. I'm just not really familiar with ABS and wasn't prepared for having to bleed that part of the system.

 

It might help you bleed them enough to take it out on a gravel road and actuate the ABS pump.

 

It might help you bleed them enough to take it out on a gravel road and actuate the ABS pump.

Since the rear and front brakes are on different systems, I decided to go ahead and try bleeding the front brakes. Those were easy and I think I got the air out. Tested the brakes, but the pedal goes to the floor before the brakes catch. So, at speed drives may be tough. However, I may consider seeing if I am brave enough to give it a shot.

It seems like the back brakes were the problem with air in the system. Hoping I can find some fix for the pedal feel at this point so I can avoid having to go to the dealer to bleed out the ABS modulator. Of course, I have no idea even if that is all that expensive or not. I'll call the dealer on Monday if I can't get the gravel road to work.

 

You don't have to go to the dealer. ANY good scanner will unload the ABS for bleeding. Most brake shops use the Snap On scanner. The Snap On, Genesys, Tech II, Mac Mentor, and the Matco Determinator will all communicate with the ABS module.

 

Here is a little info on the Actron ABS Brakescan:

This affordable alternative for diagnosing brake problems displays ABS trouble codes and definitions on an easy to read backlit display. ABS Brakescan eliminates guesswork and helps identify the parts required for brake repair.
Systems diagnosed include wheel speed sensors, ABS solenoids, the brake control module, ABS pump motor, vehicle speed sensors and more.
This simple to use scan tool plugs into the vehicle's OBD II port and provides coverage for most OBD II domestic vehicles 1996 and newer (GM, FORD, and CHRYSLER). ABS Brakescan is updatable online, features an ABS code library, retains the most recent vehicle scan, and has intuitive help screens.

ABS Brakescan includes: CP9449 handset, detachable vehicle cable, a durable/soft carrying case, and a quick start manual. Optional battery power enables ABS Brakescan to save and view data when not connected to the vehicle.

I typed this directly from the introduction page of my booklet, I couldn't get it to down load. I am like you KirkW, even if I can't fix it I would still like to be able to diagnose it and sometimes actually be able to fix it. It is brand new to the market so there are still some bugs they need t work out, but I have already used mine twice and I have only had it a month. Hope this helps you out, and I know you won't regret the purchase.:great:

Will this tool cycle the ABS valves when bleeding the brake system? I did not find anything in the online instructions concerning brake service.

 

No it would not cycle the bleeding valves, the only thing to my knowledge that will do that is the Tech 2. Now it does say on some vehicles that it will have more functions than others, but I mainly use for diagnosing the ABS.

 

What about if you bleed the brakes with this www.motiveproducts.com they have used this on the TRUCKS TV show and said nothing about the ABS, also the instructions for this don't say anything either about the ABS. I have this and have used it on my wifes '03 Mazda 6 and it works fantastic!

 

Motive

I have the Motive Power Bleeder. It's nice for 1 man operation. Much better than using a Mighty Vac. It's good for full system bleeds and when you don't have a helper handy. I use it for applying pressure to the system more than actually putting brake fluid in it. You can use it with or without fluid.

It does not trigger the ABS system at all. You are bypassing ABS with this or any bleeder.

One thing you can do for a poor mans ABS bleed. Bleed the system. Take the car out on a back road and stand on the brakes several times forcing the system to engage ABS. A wet road typically makes it really easy. Then go bleed some more fluid. If there are air bubbles trapped in the ABS this will help push them out. OR when all else fails just go to a shop with a Tech II bleeder and pay them. You can still bring your own fluid if you don't want their off the shelf stuff.

 

Pad change

Hi Sorry to hijack the thread but it sounds like this mite be my problem. I have a 95 2500 chevy and I changed the front pads. I did the passenger side and it seemed O.K. then I did the drivers side and when I pressed on the peddle to set the front pads It has been like there was air in the system. All i did was push back the piston to install the new pads so I never opend anything to get air in there. The flluid in the reservuar was very dark and had like little drops of like a slime. I bled the brakes till it got clear and still the peddle is mushey and gos to the floor. Since then I have removed the master cyl. and cleand it out and again bled averything to no avail. It feels like it's got air. How could air gotten in the system without opening it? Please help I' 57 years old and this is not the first brake pad job I've done It's the dumbest thing I've seen .:grrrrrr::grrrrrr::grrrrrr::grrrrrr:

 

Exactly the same happend to me with my 07 Suburban!
And now I cant get any pressure at all Just constant bubbles

 

For me, after changing the front brake pads and rotors and then having a problem with an intermittent mushy pedal and loss of brake fluid with no visible leak, I ended up replacing the master cylinder and the power brake booster. You haven't mentioned losing brake fluid, so if that isn't an issue then maybe you need to replace the master cylinder?

Also, as was suggested to me, you may want to check your rear calipers and see if they are leaking into the drums.

If your '95 has ABS, I think it would be the rear-only system and I'm not sure what to look for with that as far as bleeding brakes. With my '99, I've had to bleed the system about 3 times to get rid of the air and get a good pedal feel. The air was always in the rear lines, not the front.

Lastly, once you pull the master cylinder you expose the system to air. If you didn't bench bleed the master cylinder, you add a lot of air into the lines. Maybe try bleeding the back brakes to check for air bubbles could help.

 

Friggin chevy brakes

Ya you just have to keep bleeding those things , if nothing else you will have the satisfaction of flushing the system which isnt a bad idea either be careful if you run the hydraboost that you do not push the pedal to the floor as it will take out the front seal i use a vacume bleeder and pushed the pedal to bleed mine and it took about a quart per side a couple of trips of slamming on the brakes and four times of bleding that was with bench bleeding the master cylinder and not having air in the abs what a pain in the yahoo these systems are for the birds and under rated for the applications they put them on

 

one component that has been a product of modern technology is the Actron scan tool. With this device, you'll be able to determine what trouble your engine is going through. a modern tool that's designed to display, record, and playback diagnoses of your on-board engine computer. It's able to read and erase diagnostic trouble codes that are produced by your car's system. Once it's done that, the device alerts you of the problem through the use of audio prompts which is released into your dashboard. Also, since the product comes in different designs and styles, you're assured that the scan tool will be able to communicate with all vehicle types while complying with US emission standards.

 

Just to let everyone know you don't need a scan tool to bleed the ABS system. Just put the truck up on jackstands and put it in gear run it and hit the brakes a few time and the ABS will activate bleeding the system. Then bleed like normal. This works I did it yesterday!

 

What "speed" did you have to get the truck to for the ABS to kick in?

 

WITH THE TRUCK ON JACK STANDS i RAN UP TO 55MPH THEN HIT THE BRAKES. I DID THIS ABOUT 5 TIMES.

 

Did you get good results and a firm pedal? I HATE my mushy brakes!

 

Just to let everyone know you don't need a scan tool to bleed the ABS system. Just put the truck up on jackstands and put it in gear run it and hit the brakes a few time and the ABS will activate bleeding the system. Then bleed like normal. This works I did it yesterday!

Very interesting method. I've been trying to bleed all the air out of a 1999 dually for a long time now and haven't been successful. This might be an easy and effective way to solve it. It's definitely free to try.

 

Crawdaddy did this method work for you?

 

Christopher, have you tried this method yet?

Or are you waiting for some warmer weather?

I'm about 50 miles from town and don't want to start this if something might cause Murphy to give me another pain in the rear. The Eldo is also down with a leaking radiator so I would be stuck if I immobilized the truck.

Ted

 

Just to let everyone know you don't need a scan tool to bleed the ABS system. Just put the truck up on jackstands and put it in gear run it and hit the brakes a few time and the ABS will activate bleeding the system. Then bleed like normal. This works I did it yesterday!

was this on a 4x4 and did you have all wheels off of the ground?
If it was a 4x4 did you have it locked in?