Fluid Replacement - Good PM Practice or Waste of $$

[Pops946]

Brake Fluid is in the Maintenance Schedule, see footnote 5 (pink oval around it)

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Thanks, all, for the good advice and references! This is consistently a friendly and exceptionally helpful forum!

 

[jfoj]

Removing the brake caliper bleeder screws would require bleeding the brake system, including the ABS unit with a GM Tech-2, as air would be introduced into the system - and probably adding more brake fluid.

Putting anti seize compound on the caliper bleeder screws' threads would risk contaminating the brake fluid in the system.

Anti seize would not risk contaiminating the brake fluid if done correctly with only adding on the threads and you would likely bleed/flush some fluid out of the system while doing this. Flushing fluid out can even be performed via gravity as well.

The ABS unit would not have issues as long as the master cylinder does not get low enough to introduce air into the system. Additional, the Tech-2 is not the only tool that can be used for ABS brake bleeding, there are plenty of 3rd party tools that offer ABS brake bleeding options. Additionally the majority of the time you can perform a full system brake bleeding, less ABS internal fluid flush, without a tool to activate the ABS system, as long as you limit the air in the upstream portion of the brake system. Even if you do get air in the upstream system, the majority of the ABS systems bleed off fluid in parallel to the brake system, so when inactive or not going through a self test they tend to not impact the primary fluid path to the brake calipers.

 

[jerry455]

The Tech 2 will not work on the 2021 and newer trucks. They are global B architecture. As someone who just had to replace a transmission in a 2021 Suburban that I bought less than a year ago with 70,000 miles on it, I say change the fluids. If you are keeping the vehicle, change them more often. It seems the newer trans fluids additive wear out sooner. I have always been taught to change fluids as preventive maintenance. Don't be so ******* the dealer. The HD trucks still use hydraulic power steering.

 

[jfoj]

@jerry455

Transmission failure was likely more due to a faulty valve body with worn valve bores and internal valve body leaks. ALL of the 10 speeds are possible subjects for these failures. I predict the 2023+ transmisison will have these same problems and probably be recalled for the TCM software update within the next 12-18 months.

Also agree that the "Lifetime" transmission fluids are BS. Understand that the fluid in the transmission will last exactly the lifetime of the transmission!!!

Denpending on how you use the vehicle the transmission fluid should probably be changed between 25k and 50k miles. If using vehicle for towing and/or hauling on a regular basis, recommend 25k mile fluid change intervals.