Bleeding ABS module

[Oro_O]

I am working on a 2010 GM vehicle, all appearance is air in the ABS module (car has sat a while, neglected/improper maintenance). I have not had to bleed an ABS module before and have one question - where to get adapters to pressurize the reservoir.

I'm not finding anything googling or checking parts suppliers on hardware for this. I understand the use of the Tech module to do autobleed, etc., just not finding the right hardware OR actually a really good DIY guide that doesn't skip the small points like that.

 

[14Accent]

Just bleed all 4 corners like normal. Unless a valve inside the module is stuck, the air should be purged that way. Otherwise, you'll need a scan tool to activate the ABS motor and solenoids to get the air out.

 

[chemman]

You can always do what I did when needed to bleed the air out of my brake system after replacing several brake lines - find a low traveled gravel road, get up to speed and slam on the brakes to work the ABS system and get the air out. Not elegant, but it worked to get any air that might have gotten stuck in the ABS unit out. Brake pedal sure firmed up after the 3rd or 4th stop.

 

[slacktide_bitog]

WOw you still have to bleed out ABS modules?

The only cars I know of that required that were some Hondas of the early 90s, when ABS was a new thing

 

[nthach]

Originally Posted by chemman
You can always do what I did when needed to bleed the air out of my brake system after replacing several brake lines - find a low traveled gravel road, get up to speed and slam on the brakes to work the ABS system and get the air out. Not elegant, but it worked to get any air that might have gotten stuck in the ABS unit out. Brake pedal sure firmed up after the 3rd or 4th stop.

That's what I had to do with a old Tahoe that had the Kelsey-Hayes 4WAL ABS system. I had no access to the Tech II or a bidirectional scan tool to cycle the ABS modulator. So off to a vacant parking lot I went and a few hard, sudden stops later I rebled the brakes. No problems after that.

There's another quirky GM ABS system that also needed the Tech II to "home" the pistons in the modulator. Supposedly the trick around that is to start the car, wait for the modulator to cycle the pistons and go on a quick drive to let the system carry out its diagnostics without activating the ABS.

Thankfully, I don't deal with those GMs anymore. GM stopped using those weird Delco Chassis or Kelsey-Hayes ABS in favor of Bosch or ATE(Conti). TRW bought out Kelsey-Hayes.

 

[Hall]

My G35 FSM - and I'd guess this applies to all Nissans and Infinitis of that era - just says have the engine off and 'disconnect' the ABS module. I'm sure this isn't a Nissan design but they have a locking lever that unplugs the module (from battery power ?) and when you do this, I have to presume it allows the ABS module to go into some sort of "pass-thru" mode. Then you bleed/flush the lines like normal.

 

[nthach]

ABS modulator always has the ability for fluid to travel through them. I've never heard of that. It's only the weird GM systems that need scan tools to exercise them and the brake-by-wire on Ford and Toyota hybrids that follow a procedure that has you manually bleed the front brakes, then use the brake actuator to push fluid through the rears followed by a "line clear and refresh".

 

[benjy]

a motive power bleeder is an excellent reasonably priced one man system with adapters for many if not all vehicles!

 

[AVB]

Originally Posted by chemman
You can always do what I did when needed to bleed the air out of my brake system after replacing several brake lines - find a low traveled gravel road, get up to speed and slam on the brakes to work the ABS system and get the air out. Not elegant, but it worked to get any air that might have gotten stuck in the ABS unit out. Brake pedal sure firmed up after the 3rd or 4th stop.

I have had to do that to a lot of vehicles, I mostly do it in grass.

I bought a HT200 bluetooth scan tool at walmart. It was $50 and you can choose 1 car manufacturer for a free lifetime software subscription, each additional make is $15 a year for the software. It requires a android or apple device and does abs bleeds, programs keys and tpms, resets oil change indicators, calibrates electronic throttles, regens. calibrates steering angle sensors, tire pressure thresholds, change tire size on some vehicles and a few other things. It is a repackaged Autel AP200.

We have to do abs bleeds on Chrysler products, our procedure is to follow the prompts in witech. Someone has to hold the brake pedal down and click continue on the laptop and someone has to open the front right and right rear bleeders when prompted.

 

[Y_K]

Originally Posted by AVB
I bought a HT200 bluetooth scan tool at walmart. It was $50 and you can choose 1 car manufacturer for a free lifetime software subscription, each additional make is $15 a year for the software. It requires a android or apple device and does abs bleeds, programs keys and tpms, resets oil change indicators, calibrates electronic throttles, regens. calibrates steering angle sensors, tire pressure thresholds, change tire size on some vehicles and a few other things. It is a repackaged Autel AP200.

Thank you very much for sneaking in this micro-review. Very encouraging trend indeed.

 

[AVB]

Originally Posted by nthach
ABS modulator always has the ability for fluid to travel through them. I've never heard of that. It's only the weird GM systems that need scan tools to exercise them and the brake-by-wire on Ford and Toyota hybrids that follow a procedure that has you manually bleed the front brakes, then use the brake actuator to push fluid through the rears followed by a "line clear and refresh".

I just remembered that GM was talking about doing away with brake master cylinders a year or so back (I am fairly sure I saw it discussed here), I don't know if they have yet. I was told that Chrysler could do away with master cylinders, the ABS module already controls everything. The master cylinder is mostly just the human interface to maintain the traditional feel of the brake pedal.

 

[AVB]

Originally Posted by Y_K
Originally Posted by AVB
I bought a HT200 bluetooth scan tool at walmart. It was $50 and you can choose 1 car manufacturer for a free lifetime software subscription, each additional make is $15 a year for the software. It requires a android or apple device and does abs bleeds, programs keys and tpms, resets oil change indicators, calibrates electronic throttles, regens. calibrates steering angle sensors, tire pressure thresholds, change tire size on some vehicles and a few other things. It is a repackaged Autel AP200.

Thank you very much for sneaking in this micro-review. Very encouraging trend indeed.

You are welcome, I haven't had much time to really use it much and test all of the functions. I had to buy it when my girl friend's Jeep went into limp mode while we were on vacation 400 miles from home. It has a lot of capabilities for the price. The only negative I can really point out for now is that it is a little slow to load and navigate through the menu.

 

[nthach]

Originally Posted by AVB
Originally Posted by nthach
ABS modulator always has the ability for fluid to travel through them. I've never heard of that. It's only the weird GM systems that need scan tools to exercise them and the brake-by-wire on Ford and Toyota hybrids that follow a procedure that has you manually bleed the front brakes, then use the brake actuator to push fluid through the rears followed by a "line clear and refresh".

I just remembered that GM was talking about doing away with brake master cylinders a year or so back (I am fairly sure I saw it discussed here), I don't know if they have yet. I was told that Chrysler could do away with master cylinders, the ABS module already controls everything. The master cylinder is mostly just the human interface to maintain the traditional feel of the brake pedal.

I've seen that - it's GM's interpretation of brake-by-wire/electronically controlled braking that Mercedes/Bosch introduced, then it was copied and adapted by Toyota for the Prius and the rest of their hybrid line. In those systems, you have a stroke simulator that emulates the feel of master cylinder. The Mercedes system can brake individual wheels and adjust force/bias dynamically. It can even pulse the brakes slightly to dry them off if the wipers are activated. It was ahead of its time but also very problematic.

Toyota's take on Mercedes Sensotronic called ECB on their hybrids works a little differently. It's key to allowing regenerative braking to work. The hybrid control ECU and brake actuator work together. It takes a pressure reading from the brake actuator's stroke simulator to gauge brake effort. The hybrid control ECU then determines the regen/service brake blend. The only time the backup master cylinder comes into play is when there's a brake actuator failure - which also disables regen.

 

[clinebarger]

I had a 2015 Impala come in last week (Recent auction purchase by a client), Fins showing on the left front rotor, Caliper pistons popped out. Completely out of brake fluid.

The automated bleed procedure calls for a pressure bleeder, I don't have one & don't do enough brake work to justify one. Bench bleeding the master & conventional bleeding methods had no effect.

The old "Hose in a jar of brake fluid & pump" trick finally did it!

 

[Oro_O]

Originally Posted by clinebarger
I had a 2015 Impala come in last week (Recent auction purchase by a client), Fins showing on the left front rotor, Caliper pistons popped out. Completely out of brake fluid.

The automated bleed procedure calls for a pressure bleeder, I don't have one & don't do enough brake work to justify one. Bench bleeding the master & conventional bleeding methods had no effect.

The old "Hose in a jar of brake fluid & pump" trick finally did it!


Man, I wrestled with fixing this; this is the kind of answer I wanted. Otherwise, a metric f-ton of nonsense response here! I had to do it in a short time so this i what I did. I will lay this down for people who have to do it quickly.

1st, I found I could use my garden weed sprayer to give a constant 30psi. I I just took off the week wand and put the hose up to a rigged pressure gauge. I could not find a kit less than $200 to do the job, but with about $15 dollar of gauge and hardware, I was able to fabricate an assembly to do the job. I hope this helps someone else; took me a bit of time to engineer.