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.

 

[SuperOldSchool]

I do brake flushes every 1-2 years.
Trans fluid should be every 30k with the 6,8,10 speeds (my opinion).

See my changes fluid below:

Changed my filter and fluid on 8l90 8 speed today

I followed a YouTube video and changed my 8l90’s filter and fluid today. I had dealer do the first time at 45k. 34k later it’s my turn. I bought a fluid extractor to suck most out of the pan first. The most time consuming step was getting the darn heat shield removed. The rest was easy. I...

www.tahoeyukonforum.com

 

[steiny93]

Think this is good preventive maintenance or the dealer extracting cash?

I follow GM's schedule; I'd only go severe schedule if the vehicle is actually in severe duty.

 

[WalleyeMikeIII]

I follow GM's schedule; I'd only go severe schedule if the vehicle is actually in severe duty.

I’d contend most grocery getter uses of this vehicle constitute severe; as short trips on the 6.2 don’t get the oil up to temp.

 

[RogerK]

Hey, all. Got my wife a ‘23 Tahoe Premier 5.3 about 2.5 yrs ago. Just turned 30k, mix of local & highway driving. Dealer recommends replacing all the fluids at this time - transmission, power steering, brake and coolant. Think this is good preventive maintenance or the dealer extracting cash?I’m to an age where I no longer want to do this sort of work myself. Think they want about $700 for this, cabin & engine air filters and new wipers. Filters & wipers I can still do ok. Thanks for any thoughts & experience.

Just changing my transmission fluid was more than that.

 

[jfoj]

I’d contend most grocery getter uses of this vehicle constitute severe; as short trips on the 6.2 don’t get the oil up to temp.

Logged the oil temp recently when the ambient temps we 80F and it still took approximatly 20 minutes of driving for the oil to come up to temperature! Larger oil capacity has some benefits, but also has some drawbacks.

 

[viven44]

Maybe a different perspective from someone who has resuscitated many barn finds.... its quite amazing how the different systems work after all these years and what does/doesn't survive the ravages of time. Engine oil is obviously bad, when I remove the drain plug there is a lot of condensation that pours out first, coolant is surprisingly usually good, as long as a good mix was left in there, transmission fluid is always good even after an extended period especially considering the old systems were "open", brake fluid is garbage usually and takes out all the stuff with it (seals in master, calipers, wheel cylinders)...

A job not done is better that a job half done, if you plan to keep your vehicle for about 15 - 20 years, stick to the normal use case service intervals and you will help yourself dearly (and then discretion by testing on top of that on most things!) unless you are driving in a lot of dirt roads, extended idling in hot weather, towing, and hauling which is the classical definition of severe use.......

You are more likely to mess up something by getting stuff messed with by a “code reader” as I saw being described in a post yesterday. Maybe brake fluid because it’s a safety item, but even that not at the severe interval.

About the claim of severe use, I’d like to understand how short tripping can and affect anything except engine oil. Everything else is a closed system, and moisture is usually the aggressor in an open system. I can possibly see transmission fluid, but even that is closed unit these days.

Coolant is relatively easy to replace, but you can also test it before needing replacement just a simple multimeter for electrolysis, and also you can check mix with a cheap $5 hygrometer.