Sorry it's been a bit since I checked back. As for a trick with the ABS from a '97 blazer ABS, I was talking about my Auto Eginuity Scan Tool, and I think I may be able to trick the scanner into thinking it's a newer blazer (that the scan tool will actuate) and actuate the ABS bleed procedure that way. Without getting into too much detail you can tell the computer what the vehicle actually is (or lie in my case). For that year blazer the scanner can't even tell what the car is when it pulls the VIN number from the car because there is some overlap between Blazers, Vans, and something else in that model year. I don't think there is any overlap in production date though so this theory may not work.

From my limited knowledge it would appear that most 4wd trucks in those 97-01 (could be wider range of years, I haven't checked any further) seem to all have the same abs pump, I think the 4WAL. So I doubt by lieing to the scanner that I'll damage anything, it's just a matter of getting the ECM to initiate the procedure.

As for a trick to actuate the ABS procedure without that scan tool, well I've got none. Just to let you know the thing did work on the Silverado and basically here is what happened. The computer initiates the procedure and tells you to push the brake. Push the brake and the computer turns on the abs pump for a few seconds. The pump stops and you are suppose to release the pedal. The computer tells you to push the pedal again and something else kicks on, I assume it actuates the valves in the abs system. Release the brake pedal again. Press it one more time and you're done. That's all it does.

My father however has been talking to people he knows who do nothing but work on cars for a living and basically what they have told him is that you don't need a computer, you just have to be persistent. Apparently you just crack open the bleed screws and let it run, and run, and run, and run, and when you think you couldn't possibly let it run anymore, keep letting it run because some of these systems especially the Silverados are a pain in the rear to purge of bubbles.

Of course if you've got rear drums, make sure they are adjusted up, because I've already been down that road, where I thought I had air in the system and my rears were just not turned up enough, since they stopped adjusting on their own.

So Smitty, I know what you're talking about with a craptastic vehicle, as mine was the same way, until we got past all the stupid failures and now we're in the range of just wear and tear items that are easily diagnosed with a little old fashioned car knowledge. For a few years there it seemed like that car would have liked nothing more than to sit in a junk yard, but the fight got personal and we repeatedly brought it back from the verge of scrap.

Anyway I bought my scanner for the same exact reason as you and I have used my scanner much less than I thought I would. Probably shouldn't complain about that. But it is a nice tool to have lying in wait for when you need it. Also with this eye opening experience I think I'm going to appreciate this scanner much more than I did previously.

I wouldn't buy that $70 card though unless you need it. Otherwise it will sit an collect dust and you could do alot of fun things with that $70 bucks. That's just my opinion though, do what is right for you.

 

Thanks for the detailed run through - I think that now we have a great "how to" going for this system... it's for sure the most detailed info I've found doing the net-search & forum searches. Still chafes my shorts to think they expect you to buy a scan tool that costs more than the vehicle is worth. I'm going to cut & paste your last post into my other thread for benefit of those with the same system as mine.

Thanks again!

 

Not a problem, this forum has bestowed upon me alot of knowledge and helped me solve alot of my problems, so giving back is really the least I can do.

When I get around to testing my theory I will post back and let you know how it goes. I'm hopeful it will work, but I've been wrong quite a few times before.

Anyway the only thing that keeps me from cursing the GM engineers on this one is the fact that those years were really a transitional time when they were working towards using the computer to control the vehicle systems. They were teething and they needed to figure some stuff out, cause lets face it you rarely hit a home run on your first try(s).

For instance sometime around our years, the ABS controller used to be a standalone piece of electronics, but at some point it was integrated into the ECM. This is why I believe that our year is forsaken on both a manual method and by some scan tools.

Truth be told, the stage that our '97s are at is quite primitive when compared to a newer model. The latest model I've hooked it to is a 05 and the wealth of knowledge available by just plugging in the scan tool is staggering.

Of course understanding what the trouble codes mean is another story all together, as GM still hasn't figured out how to put together a decent shop manual. They could learn a few things from Subaru. Mainly the KISS principle.

When I look at the number 3 spark plug behind the steering column, or the 4wd vacuum hub engagement, it would really satisfy me to hit someone responsible for that design, just for all the headache they have caused us.

The computers though...I'll give em a pass on that one...for the time being.

 

Yeah I hear that on the KISS principle. My Silverado service manual is 4 books that stand almost 2' high stacked on top of each other. Open one section, and it tells you to reference 2 other manuals. Really stupid setup. I think they do it on purpose thinking it will discourage DIY'ers and generate more revenue at the dealerships.

All it REALLY does is send everyone to another brand. I'll never buy another new GM again for that reason, as I work on all my vehicles. If they make that hard for me, I go elsewhere.

 

Gravity bleed is a sure way to get all air out, first passenger rear, second driver rear, third pasenger front, forth driver front. It must bled in this order. Put a piece of clear tubing on each bleeder as you bleed them, point the tubing slightly upward then crack the bleeder one turn. You can watch the air bubbles come out. Put something under the bleed tube to catch the fluid, when the bleeder runs clear for two minutes it is done. It takes me about one hour to bleed all four. Then you will feel a hard pedal with no give and know the air is out. Gravity rules.