Intermittent Braking Loss on '16 Yukon

[Yukon John]

I have suddenly experienced occasional "Dead Pedal" at low speeds and when stopped on a hill either headed up or down an incline. I did a bit of research and learned that there is a TSB for 2015~2017 Full Size GM Suv's that address this condition. Seems that the fix requires replacing the vacuum pump, brake booster as well as the master cylinder, etc. I am still under the drive train warranty and am wondering if anyone on the Forum has had this issue and taken their truck into a dealer for the repair/correction?

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#PIT5361B: Diagnostic Tip - Additional Brake Pedal Effort - (Jun 28, 2016)



Subject: Diagnostic Tip - Additional Brake Pedal Effort


Models: 2015-2016 Cadillac Escalade Models 2014 Chevrolet Silverado 1500 2015-2016 Chevrolet Silverado 1500, Suburban, Tahoe 2014 GMC Sierra 1500 2015-2016 GMC Sierra 1500, Yukon Models


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern
In some rare situations, a customer may comment on a hard brake pedal or that increased effort is needed to depress the brake pedal. Also, in some cases a tick or ticking noise may be heard, which may sound like an exhaust manifold leak. While performing normal diagnostics, fluid may be found in the brake booster and/or the booster vacuum line.



Important: Pay close attention to the fluid and if it is determined to be engine oil, it could be coming from the vacuum pump. The vacuum pump is belt-driven and mounted to the side of the engine block. It is lubricated by pressurized engine oil.



Recommendation/Instructions
Ifengine oil is found, it is important the following parts are replaced. If not, the condition will return.

1. Vacuum Pump
2. Vacuum Line between the booster and the pump
3. Brake Booster
4. Master Cylinder
5. Vacuum Pump Belt"

Thanks in advance.

 

[Doubeleive]

that sounds like a really bad design, I wonder what happens when the vacuum pump decides to completely blow the seal and send a surge of engine oil into the brake booster.
why is the vacuum pump even designed in this manner? there should be no possible way for engine oil to get into your brake system

 

[Bai2020]

Yes, we had this happen in our 2016 tahoe... twice. The first time at around 30k miles and the 2nd time around 33k miles. We're now at 40k miles and haven't had any issues. For us, it would only happen at very low speeds in scenarios like being in a line of cars at a stop sign where we would constantly be applying brake pressure then moving forward slowly. Luckily never at high speeds. Scary though when you're in traffic moving slowly and have to almost stand on the brake pedal to stop. I believe the entire list of parts was replaced each time. Not sure why it failed a 2nd time, my wife almost wanted to trade in the car, obviously a serious safety issue.

 

[Yukon John]

Yes, we had this happen in our 2016 tahoe... twice. The first time at around 30k miles and the 2nd time around 33k miles. We're now at 40k miles and haven't had any issues. For us, it would only happen at very low speeds in scenarios like being in a line of cars at a stop sign where we would constantly be applying brake pressure then moving forward slowly. Luckily never at high speeds. Scary though when you're in traffic moving slowly and have to almost stand on the brake pedal to stop. I believe the entire list of parts was replaced each time. Not sure why it failed a 2nd time, my wife almost wanted to trade in the car, obviously a serious safety issue.

Thanks for your reply....I will get in touch with the local GMC dealer tomorrow.

 

[Yukon John]

Thanks for your reply....I will get in touch with the local GMC dealer tomorrow.

Ok....at dealer now...getting estimate...not covered by engine drive train warranty ! Stay tuned...

 

[dbbd1]

Ok....at dealer now...getting estimate...not covered by engine drive train warranty ! Stay tuned...

Never mind...

 

[RST Dana]

Ok....at dealer now...getting estimate...not covered by engine drive train warranty ! Stay tuned...

I would contact the BBB since this is a real safety issue.

 

[Yukon John]

OK...remember the old expression " The pen is mightier than the sword" ? Soooo...while I was waiting in the "Customer's Lounge"...I called GM Customer Service and explained to them what was going on. The young lady with GM put me on hold for a few minutes while she verified my VIN and odometer mileage (On Star)...got back to me with a call transfer to a "Customer Service Manager". The CS Mgr gave me a case number, called the dealer while I was on hold...came back on the line and told me there would be NO CHARGE...and I should go back to the service department. Before I could get across the building...I heard my name called out on the PA system to please report to the Service Department. I was met by my service advisor and the Service Manager confirming what GM Customer Service had told me...the repairs would be handled under warranty for Engine and Drivetrain at No Charge to me.

Lots of smiling faces and hand shakes later...within about 2 hours I was on my way. Oh...they also gave me a discount on a full 8 quart full synthetic oil and filter change fo $60 !!!

GMC Truck Division...HELL YES !!!

 

[Miami-Dade]

OK...remember the old expression " The pen is mightier than the sword" ? Soooo...while I was waiting in the "Customer's Lounge"...I called GM Customer Service and explained to them what was going on. The young lady with GM put me on hold for a few minutes while she verified my VIN and odometer mileage (On Star)...got back to me with a call transfer to a "Customer Service Manager". The CS Mgr gave me a case number, called the dealer while I was on hold...came back on the line and told me there would be NO CHARGE...and I should go back to the service department. Before I could get across the building...I heard my name called out on the PA system to please report to the Service Department. I was met by my service advisor and the Service Manager confirming what GM Customer Service had told me...the repairs would be handled under warranty for Engine and Drivetrain at No Charge to me.

Lots of smiling faces and hand shakes later...within about 2 hours I was on my way. Oh...they also gave me a discount on a full 8 quart full synthetic oil and filter change fo $60 !!!

GMC Truck Division...HELL YES !!!

I am definitely going to your dealer for my next service as soon as I get off my road trip in the next couple of weeks. My present dealer Schumacher Chevrolet-GMC on North Lake Blvd in North Palm Beach is horrible.

 

[dbbd1]

I am definitely going to your dealer for my next service as soon as I get off my road trip in the next couple of weeks. My present dealer Schumacher Chevrolet-GMC on North Lake Blvd in North Palm Beach is horrible.

Don't forget, that was after the GM phone call. Of course they are going to be nice, after they get spanked by daddy GM.

 

[Yukon John]

One additional addition to this story....GMC Truck Division sent me a $100 service/repair voucher to be used for future required maintenance or repairs.

Honestly....I don't think I have ever been treated as well as I have with this issue by any other manufacturer or dealer.

 

[Jeff Potter]

Add me to the list of "HOLY SH%T!, what just happened to my BRAKES" list. Vacuum pump fail at low speeds. Getting replaced this coming week.

 

[kdsimms]

OK...remember the old expression " The pen is mightier than the sword" ? Soooo...while I was waiting in the "Customer's Lounge"...I called GM Customer Service and explained to them what was going on. The young lady with GM put me on hold for a few minutes while she verified my VIN and odometer mileage (On Star)...got back to me with a call transfer to a "Customer Service Manager". The CS Mgr gave me a case number, called the dealer while I was on hold...came back on the line and told me there would be NO CHARGE...and I should go back to the service department. Before I could get across the building...I heard my name called out on the PA system to please report to the Service Department. I was met by my service advisor and the Service Manager confirming what GM Customer Service had told me...the repairs would be handled under warranty for Engine and Drivetrain at No Charge to me.

Lots of smiling faces and hand shakes later...within about 2 hours I was on my way. Oh...they also gave me a discount on a full 8 quart full synthetic oil and filter change fo $60 !!!

GMC Truck Division...HELL YES !!!

I have this issue but its intermittent (and of course does not happen at the dealership). I guess I'll be calling GM Customer service also (800.222.1020)

 

[stormin]

I have had the same issue with my 2016 Tahoe ltz...started approx. 2 months ago...
low and behold... a couple of days ago .. I get a letter in the mail from generous motors...making me aware of this possible problem and if I do experience this... they will replace the vacuum pump under warranty and have extended the warranty on this issue I believe for 6 years from the date your vehicle was placed in service or 116,000 kms… which is approx. 70,000 miles.
so if you have this issue and haven't received notice from GM... go check with your local dealer and inquire about this campaign.

take care all!!

 

[PG01]

that sounds like a really bad design, I wonder what happens when the vacuum pump decides to completely blow the seal and send a surge of engine oil into the brake booster.
why is the vacuum pump even designed in this manner? there should be no possible way for engine oil to get into your brake system

Actually, if its not taken care of promptly, that’s exactly what will happen and you need to swap the booster too.