Recall - Vacuum Pump May Decrease Power Brake Assist

jay webb · September 14, 2019

4 hours ago, aaronarf said:

In hind sight, my pump has been showing signs of failure for the last 10-15K miles, unfortunately for me I was outside of the 72K miles when the TSB was released. That being said, I do not agree that all failures are related to dirty oil or lack of maintenance it could accelerate the inevitable though. I change my oil regularly -- 11 times at an average of 7K miles over 78K miles using Mobil 1 EP (Last 6 changes) & Pennzoil Ultra Premium (First 5 changes). The AFM was deactivated within the first 7K miles via Range Device.

I was debating on trading in my truck on something else, or fixing the problem. Today I ordered the new pump, and scheduled an appointment for the ECM re-flash Monday morning. I am going to install the pump Monday myself after my re flash, hopefully the install won't be too difficult!

ok here is what i do to do them. you need to remove the air intake to the throttle body, remove the belts. heres the kicker on the ac/vacuum pump belts. they are stretch belts , meaning there is no tensor. using a ratchet and a 24mm socket on the crank bolt and a pry bar or similar tool you can remove these belts. turn the engine over with ratchet and use prybar to wedge the belt off. going back the same way but is a bit more difficult. they have to go on in a certain order, vacuum pump, ac then main belt. vacuum pump belt you can hold by hand on the pulley and turn the crank. ac belt i typically put the belt around the compressor and half around the crank and zip tie to crank to hold in place and turn the engine over to pull it on all the way.

i find it easier to remove the steering shaft between the part that comes through firewall and down to steering gear. its a 15 mm on the upper part and a 11 mm pinch bolt on the lower part attaching to the gear.

this provides alot of room.

there is a vacuum line that runs to the pump remove it , position out of the way. there is a wiring harness there too you can gain some slack if you pull it from the clips that hold it in place. then on the pump it self is 4 13 mm bolts , remove them and the gasket. it will drain a good amount of oil. and then install new pump/gasket and finished putting everything back.

i do these from underneath the truck on a lift but they can be done from the top. i typically do them in 30 mins. but ive done so many of these and have swivel sockets , electric impact drivers / cordless tools etc.

Bob2C · September 14, 2019

I have an 18 that is not recalled. Does this mean I have the updated pump?

Sent from my iPhone using Tapatalk

aaronarf · September 15, 2019

2 hours ago, jay webb said:

ok here is what i do to do them. you need to remove the air intake to the throttle body, remove the belts. heres the kicker on the ac/vacuum pump belts. they are stretch belts , meaning there is no tensor. using a ratchet and a 24mm socket on the crank bolt and a pry bar or similar tool you can remove these belts. turn the engine over with ratchet and use prybar to wedge the belt off. going back the same way but is a bit more difficult. they have to go on in a certain order, vacuum pump, ac then main belt. vacuum pump belt you can hold by hand on the pulley and turn the crank. ac belt i typically put the belt around the compressor and half around the crank and zip tie to crank to hold in place and turn the engine over to pull it on all the way.

i find it easier to remove the steering shaft between the part that comes through firewall and down to steering gear. its a 15 mm on the upper part and a 11 mm pinch bolt on the lower part attaching to the gear.

this provides alot of room.

there is a vacuum line that runs to the pump remove it , position out of the way. there is a wiring harness there too you can gain some slack if you pull it from the clips that hold it in place. then on the pump it self is 4 13 mm bolts , remove them and the gasket. it will drain a good amount of oil. and then install new pump/gasket and finished putting everything back.

i do these from underneath the truck on a lift but they can be done from the top. i typically do them in 30 mins. but ive done so many of these and have swivel sockets , electric impact drivers / cordless tools etc.

Thank you for the tips/procedures!!! While checking out the pump and what the install will look like I realized my oil cooler lines are leaking - that looks like a helluva job? Don't want to hijack this thread I am going to PM you with a few questions if you don't mind!

jay webb · September 15, 2019

3 hours ago, Bob2C said:

I have an 18 that is not recalled. Does this mean I have the updated pump?

Sent from my iPhone using Tapatalk

i also have an 18 sierra and no i dont believe it is, you will get a noticed if you are.

aaronarf · September 15, 2019

15 hours ago, Bob2C said:

I have an 18 that is not recalled. Does this mean I have the updated pump?

Sent from my iPhone using Tapatalk

There are visual differences between the new and old style. Here is a side by side in a installation video:

RE1 · September 15, 2019

Can someone confirm specifically what is reflashed? Is it the ECM? The BCM? Guessing it’s not the TCM.

I just got a custom Diablew tune a few weeks ago. I would return the ECM and TCM tunes to stock before going in for the recall. However, I may have a problem reloading the custom tune after the recall is complete.

Edited September 15, 2019 by RE1

Grumpy Bear · September 15, 2019

34 minutes ago, RE1 said:

Can someone confirm specifically what is reflashed? Is it the ECM? The BCM? Guessing it’s not the TCM.

I just got a custom Diablew tune a few weeks ago. I would return the ECM and TCM tunes to stock before going in for the recall. However, I may have a problem reloading the custom tune after the recall is complete.

I asked this when my EPS was flashed under that recall. I was worried the learning would be reset. I was told the 're-flash' only changes the targeted line of code. It's more of a rewrite than a re-flash.

tbarn · September 15, 2019

EBCM is the recipient of the new software.

General Motors has decided that a defect which relates to motor vehicle safety exists in certain 2014-2018 model year Cadillac Escalade, Chevrolet Silverado, Chevrolet Suburban, Chevrolet Tahoe, GMC Sierra, and GMC Yukon vehicles. In some circumstances, these vehicles may have a condition in which the engine-mounted mechanical vacuum pump output may decrease over time, decreasing the amount of vacuum/power brake assist.

Dealers will reprogram the electronic brake control module with a new calibration that will improve how the system utilizes the hydraulic brake boost assist function when vacuum assist is depleted

RE1 · September 15, 2019

31 minutes ago, tbarn said:

EBCM is the recipient of the new software.

General Motors has decided that a defect which relates to motor vehicle safety exists in certain 2014-2018 model year Cadillac Escalade, Chevrolet Silverado, Chevrolet Suburban, Chevrolet Tahoe, GMC Sierra, and GMC Yukon vehicles. In some circumstances, these vehicles may have a condition in which the engine-mounted mechanical vacuum pump output may decrease over time, decreasing the amount of vacuum/power brake assist.

Dealers will reprogram the electronic brake control module with a new calibration that will improve how the system utilizes the hydraulic brake boost assist function when vacuum assist is depleted

I see.... EBCM = electronic brake control module. So ECM (engine control module) and TCM (transmission control module) are left alone?

Man, there are a lot of modules on these trucks!

Thanks!

Edited September 15, 2019 by RE1

1SLOW1500 · September 15, 2019

I asked this when my EPS was flashed under that recall. I was worried the learning would be reset. I was told the 're-flash' only changes the targeted line of code. It's more of a rewrite than a re-flash.

Yes but hard to say it dealer or service mechanic doesn't flash the pcm,tcm,bcm.
For most this isn't a issue. However us tuned vehicles it clears out the tune. Without the device and laptop we can't write the tune to vechile and drive home.
I posted on HPT forums but there is no way around this other then demanding they only flash that module.
Or you just download the update and flash it yourself.

Sent from my SM-N960U using Tapatalk

Jacoby · September 15, 2019

5 hours ago, RE1 said:

Can someone confirm specifically what is reflashed? Is it the ECM? The BCM? Guessing it’s not the TCM.

I just got a custom Diablew tune a few weeks ago. I would return the ECM and TCM tunes to stock before going in for the recall. However, I may have a problem reloading the custom tune after the recall is complete.

Why would you have a problem reloading you’re custom tune?

1SLOW1500 · September 15, 2019

Why would you have a problem reloading you’re custom tune?

I have check and asked and sent email. It will Not effect your tune. However if dealer flashes any of the pcm or tcm you will need to reinstall you tune. Some people do not own a device to do that so that was the concern.
There is a $120 device anyone can buy and $40 2 year access to gm flashes and updates and you can do as you please.

Sent from my SM-N960U using Tapatalk

Jacoby · September 15, 2019

14 minutes ago, 1SLOW1500 said:

Some people do not own a device to do that so that was the concern.

For you guys with custom tunes from actual shops I can see the concern.

The guy I quoted said he has a Diablew tune which means he has a hand held tuner. Flash it back to stock, go to dealer and let them flash whatever they want then come back home and reload the custom tune. The tuner is going to save the new tune from the dealer if they changed anything. So what is his concern?

1SLOW1500 · September 15, 2019

For you guys with custom tunes from actual shops I can see the concern.

The guy I quoted said he has a Diablew tune which means he has a hand held tuner. Flash it back to stock, go to dealer and let them flash whatever they want then come back home and reload the custom tune. The tuner is going to save the new tune from the dealer if they changed anything. So what is his concern?

Correct and for the custom tuners just save that file as stock file so you still have options to compare to custom file or go back to stock with that file.

Sent from my SM-N960U using Tapatalk

RE1 · September 15, 2019

1 hour ago, Jacoby said:

For you guys with custom tunes from actual shops I can see the concern.

The guy I quoted said he has a Diablew tune which means he has a hand held tuner. Flash it back to stock, go to dealer and let them flash whatever they want then come back home and reload the custom tune. The tuner is going to save the new tune from the dealer if they changed anything. So what is his concern?

I thought I read somewhere that a custom diablew tune is tied to the original backup on the programer. If one flashes back to stock (original backup) and takes it to the dealer who then flashes a different version of the stock ECM or TCM tune, the programer will see this new, unrecognized stock tune and not allow the custom tune to upload to the truck. I don’t know if I’m explaining it correctly as I’m not very knowledgeable with this. I may have to email Lew about this.

Edited September 15, 2019 by RE1