Jump to content

Recommended Posts

Posted

Hi,

 

I have a 2019 AT4 which is at the 5  year mark for brake fluid.  I haven't seen any posts on bleeding the brakes, just on pad replacements.  I wanted to confirm that no particular service mode is required for just bleeding, and it follows the same basic procedures as older models: add fluid, and pump out starting from RR, RL, FR, FL?

 

Thanks

Posted (edited)
1 hour ago, hoitzed said:

Hi,

 

I have a 2019 AT4 which is at the 5  year mark for brake fluid.  I haven't seen any posts on bleeding the brakes, just on pad replacements.  I wanted to confirm that no particular service mode is required for just bleeding, and it follows the same basic procedures as older models: add fluid, and pump out starting from RR, RL, FR, FL?

 

Thanks

 

 

A scan tool is required.  You have to deactivate the booster and also perform an automated bleed and hydraulic leak test.

Edited by newdude
Posted
2 hours ago, newdude said:

 

 

A scan tool is required.  You have to deactivate the booster and also perform an automated bleed and hydraulic leak test.

 

Same procedure or the old-school method on a 2009 1500 4x4?

Posted
1 hour ago, MaverickZ71 said:

 

Same procedure or the old-school method on a 2009 1500 4x4?

 

 

Old school on an 09 unless you think you need to bleed the ABS pump, there's a scan tool bleed for that.  

 

T1 trucks the booster is also the ABS module and pump and its all electronic and boost-by-wire.  The brake pedal is still attached to the "booster" but there is sensors and stuff to interpret the boost given.  

  • Thanks 2
Posted

Does that mean without the scantool on the T1's to turn off the booster, it just won't bleed, bleed incompletely, or result in other issues (CEL / malfunctions)?

Posted
On 10/30/2024 at 1:17 PM, hoitzed said:

Does that mean without the scantool on the T1's to turn off the booster, it just won't bleed, bleed incompletely, or result in other issues (CEL / malfunctions)?

 

 

To change the fluid for the entire brake system, it must be disabled.  The lines are still manually bled as normal after that, but that can not be done unless the system is disabled.  

 

Steps are:

 

- Fill the reservoir to max

 

- Unplug the level sensor

 

- Disable the booster with a scan tool

 

- Do a "base bleed" aka a traditional bleed.  GM calls for doing it with a pressure bleeder tool.  

 

- Perform an automated brake bleed with a scan tool 

 

- Disable the booster with scan tool again and repeat the base bleed to get any remaining air out

 

- Perform hydraulic system test with scan tool.  If that fails after 3 attempts, inspect for leaks. 

 

Posted

I just gravity bleed, keeping the MC full at all times to avoid ABS pump issues. 

Mostly clean fluid is better than none in the system in my personal vehicles. Drove multiple year Express vans on my job taken to over 250k miles for years than never had a brake fluid change as fleets don't do that. They just replace calipers and bleed enough to get the caliper working again when needed. 

  • Like 1
Posted

So I did a gravity bleed.. and our reservoirs are tiny! I may have let it get too low, and now I have no brakes at all.  The DIC is throwing all sorts of ESC, Brake, Trailer Brake, and ABS errors, and there is no stopping power.  Anything I should attempt before towing it to the dealer?

Posted
1 hour ago, hoitzed said:

So I did a gravity bleed.. and our reservoirs are tiny! I may have let it get too low, and now I have no brakes at all.  The DIC is throwing all sorts of ESC, Brake, Trailer Brake, and ABS errors, and there is no stopping power.  Anything I should attempt before towing it to the dealer?

 

 

I'm gonna say it...but should have just taken it there to begin with.  Scan tool is needed to bleed it.  

Posted

well deserved "i told you so".  $200 every 5 years, not worth the hassle of doing it yourself.  I just thought I'd give it a go since I had extra fluid from doing my canyon. Guess things changed quite a bit from 2017 to 2019..

Posted (edited)
6 hours ago, hoitzed said:

well deserved "i told you so".  $200 every 5 years, not worth the hassle of doing it yourself.  I just thought I'd give it a go since I had extra fluid from doing my canyon. Guess things changed quite a bit from 2017 to 2019..

 

 

Was it a 15-22 Canyon?  Those take DOT 3, Silverado 19+up takes DOT 4.  3 and 4 are compatible, sure, however, GM does spec DOT 4 in there for its higher boiling points and I wouldn't go to the lower boiling spec DOT 3.  

Edited by newdude
  • 1 year later...
Posted (edited)

I end up using GDS2 for certain GM vehicle functions, including Brake System Plunger Motor Position Sensor Learn and the Hydraulic Circuit Installation Verification when doing some of the brake repairs on Tx trucks and SUVs. Some scan tools won't run the routine(s) properly.

 

I like to flush the brake fluid on my vehicles periodically, but unless you absolutely need to perform an automated bleed to rid the EBCM of fluid, then I would recommend a manual or pressurized flush/ exchange and call it a day. Do this with the battery disconnected and you won't have to run the aforementioned routines.

Edited by carkhz316

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Latest Articles

  • Posts

    • I knew when I bought my truck that it had off road hill decent or craw control or whatever they call it and rolled my eyes at that but it gets throw on with other options my truck has, I just never had a heads up if the highway speed regular cruise setting had anything to do with the brakes and that took me by surprise. If you've ever been to the top of Pikes Peak and watched those ahead of you on the way down with their brake lights on constantly, one can guess they are probably not gearing down or not enough anyway if their vehicle will allow and a good reason their is a brake check spot part way down where they use an infra red heat gun to check how hot ones brakes are front and rear.    Your right that once one gets out of the front range by Denver and I've not been on that stretch of 285 between Denver and Fairplay myself but I know its high and Fairplay at 10000 feet, Buena Vista at 8000, it drops a bit from there but then your going back up and over the 11000 pass and Durango is at 6500 . So yes your definitely right that 6500 and a lot higher is the theme of going anywhere out in that direction from Denver but hey, the down hill sections give fantastic fuel mileage !.    I don't even look at the fuel pumps for what premium costs here, since I live on a farm and up to this point get fuel delivered I am rarely in front of a fuel pump and when I am, I am often using card lock bulk fuel stations so it tells me what the price is AFTER I buy the fuel. Looking up on gas buddy and converting to US gallons but in Canadian dollars, regular on average of the prices listed was around 5.95 and premium is around 7.00 . That was one reason I did not go for the 6.2 half ton aside from its lack of carrying/towing if one was going by the rule of using premium fuel and until recently one could only buy regular farm gas if playing the few cents off game for farm dyed fuel for a "farm licensed pickup". But yes I hear you on the fuel price difference and like the diesel theme with it often being more expensive then gas it doesn't have quite the charm to it either as it once did although right now here for some reason the price of diesel has come down more so its now inline with the price of regular gas. 
    • I agree with this assessment. As you know I’m testing longevity with vehicles for the first time. I have a few vehicles I passed to kids and grandkids. We’re all past 100K miles some approaching 170K. I’m the only one doing 5k oil changes. The rest whatever the minder says. I’m the only one doing frequent transmission service. My odyssey the trip vehicle at 200K will be finished as a trip vehicle. I recently changed to high mileage oil, Valvoline. I can’t get past the fact that all manufacturers want to claim long service life. I just don’t make sense that they would go with low weight oil for mileage. While sacrificing longevity.
    • There's absolutely a mountain of profit in catering to the "I do my own research" crowd, people who are certain they know better. And I don't mean there isn't data to support that 0w40 produces less wear product than 0w20 in an engine like the 3.0 Duramax, that only feeds them the assurance they need. Again, my whole thing with oil selection is, sure, 0w40 or 0w30 produces less wear product. Are we talking the difference between the engine lasting only 100k versus 200k? Or are we talking more like, if the engine will already go 350k on a good 0w20 regimen recommended by the OE, is using 0w40 going to get us to 355k, assuming we can even get the rest of the truck to last that long, meanwhile sacrificing the first 5y, 100k in powertrain warranty. The answer isn't easy, there are tradeoffs.   I willfully use 0w20 Dexos D for this reason, knowing that a 0w40 will produce slightly less wear. I don't believe the delta in wear product is meaningful over the lifetime of the engine, and I place much more importance on driving style and overall feeding and care of the engine as a whole. It's the mentality that someone can abstain from alcohol their whole life which is an amazing boost to health by itself, theoretically. But if they're sedentary, that lifestyle choice will most likely kill them young despite their other, concerted efforts. Maybe someone doesn't drink AND they are the perfect picture of health and activity AND they use 0w40 AND they treat their engine perfectly. If living until 130 years is the goal, sure, do that. But it's going to be a really old truck falling apart around a good engine for that last 30 years, without a doubt.   I watched Demonworks' other video on the 100k+ 3.0 Duramax that had dealer 0w20 changes on what appears to be OLM-prescribed intervals (8-10k).   The QR codes are still present and readable on the main bearings. That's how little wear it has.   That's not proof that anyone else should stick to 0w20, but it's confirmation, for me, that 0w20 is perfectly acceptable to use in these engines.
    • 1Based on independent testing of OE 0W-20 in the Peugeot TU3M Wear Test as required by the dexos1 Gen 2 specification.
    • oh ya that's good to know - I would rather use a gear than the brakes down a long hill.  I would not let cruise control take over on snow or towing a trailer for sure on hills anyway.     The other thing about the CO trip was that was all done above 6K feet for the most part, so that has to use more gas as the motor is down a good amount of power up there.   If I drove my 2016 Camaro with a very similar V8 to this 6.6 it would probably get about 23-24 on the fast run up to NE.  But the premium fuel premium is steep here in CO, so it would still only save about $40 in overall costs for the round-trip.  And you sure can't carry much gear in a convertible camaro!
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...