2015 Tahoe Brakes Fail at Low Speed

AMK · November 28, 2016

I've gotten a ton of good info, troubleshooting tips, and fixes off of this site over the last few years. Any help or recommendations are greatly appreciated. Here's my issue:

I have a 2015 Tahoe with 49K miles. Over the last few days, it has developed an intermittent issue where the bakes fail to engage at low speed. I've noticed it when pulling into parking spaces and inching forward in stop and go traffic. It feels as if there is no hydraulic pressure in the system, and I can feel the ABS pulsing the pedal when it happens. I have to stand on the brakes to get them to grab. I'm fairly handy and have probably performed over 50 brake jobs in my lifetime. Here are a few of the items I've checked:

- The brake fluid is at the MAX level in the reservoir

- Removed front wheels and brake pads are at least 50%

- Bled front brake lines to ensure there were no air pockets (steady stream of fluid)

I have not had the brakes act up at speeds over 25 mph - it always seems to have good stopping power and pedal feel at road / highway speeds. Normally this would be a straight trip to the dealer, but I have little faith in my local dealerships. Took 3 of them to finally fix an engine "tapping" in my 2014 Silverado. After I was the one who noticed a broken exhaust manifold bolt by seeing the soot on the head next to the broken bolt...

truckguy82 · December 8, 2016

Not sure if this helps, but that sounds exactly like the problem older GM vehicles had, but it was a long time ago.

Like 1995-2002 models were effected and there was a recall for it.

It was usually a wheel speed sensor or abs sensor that needed to be cleaned or replaced. (usually just needed to be cleaned)

The symptom was almost exactly what you're describing. I dealt with it on my '97 tahoe many years ago. ABS would just kick on while coming to stop, always happened under 5mph.

newdude · December 15, 2016

I've gotten a ton of good info, troubleshooting tips, and fixes off of this site over the last few years. Any help or recommendations are greatly appreciated. Here's my issue:

I have a 2015 Tahoe with 49K miles. Over the last few days, it has developed an intermittent issue where the bakes fail to engage at low speed. I've noticed it when pulling into parking spaces and inching forward in stop and go traffic. It feels as if there is no hydraulic pressure in the system, and I can feel the ABS pulsing the pedal when it happens. I have to stand on the brakes to get them to grab. I'm fairly handy and have probably performed over 50 brake jobs in my lifetime. Here are a few of the items I've checked:

- The brake fluid is at the MAX level in the reservoir

- Removed front wheels and brake pads are at least 50%

- Bled front brake lines to ensure there were no air pockets (steady stream of fluid)

I have not had the brakes act up at speeds over 25 mph - it always seems to have good stopping power and pedal feel at road / highway speeds. Normally this would be a straight trip to the dealer, but I have little faith in my local dealerships. Took 3 of them to finally fix an engine "tapping" in my 2014 Silverado. After I was the one who noticed a broken exhaust manifold bolt by seeing the soot on the head next to the broken bolt...

Have the vacuum pump and pump lines checked. Either you or the dealer should check for this. Read this below:

#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
If engine oil is found, it is important the following parts are replaced. If not, the condition will return.

Vacuum Pump

Vacuum Line between the booster and the pump

Brake Booster

Master Cylinder

Vacuum Pump Belt

Mooksta12 · February 18, 2017

I fixed my brake booster and my master cylinder on my 2007 Escalade.. does anyone know why my front brakes keep locking up on me where the car won't move?

Joeg4go · October 11, 2018

Did the OP ever determine the cause of this issue? I have a 2016 Chevy Tahoe and I have exactly the same issue. Parking is scary. The brakes are fine at higher speeds though. I have a towing package with the trailer brake assist and I would never attempt to haul something with this happening.

Tahoe02 · October 12, 2018

Are you out of warranty?

Joeg4go · October 17, 2018

Yes, I'm out of warranty. I bought it used and at 50k miles. I'm going to try to clean the mounting surface of the ABS Hub Speed Sensor as outlined in this video:

I'll update if this works...

Tahoe02 · October 18, 2018

Good luck, glad you took the initiative to search around to find a possible solution. If it works maybe it will help someone else experiencing the same problem. Please let us know if it works.

Joeg4go · October 25, 2018

Well the procedure to did not work. I borrowed an advanced OBD tool from a friend that was able to show even historical DTC faults that were not read by my cheap OBD. There were no active faults. I was also able to verify that the speed sensors were all working. I wish the OP would post what the solution was.

Tahoe02 · October 27, 2018

Did you try a Google search for the same symptom to see if anyone else posted a solution.

Riklimoguy · October 29, 2018

You have to change the Vacuum Pump. It’s a known defect with tge 15/16 Models! I changed it, and solved the problem.

makorider · January 3, 2019

On 10/29/2018 at 9:54 AM, Riklimoguy said:

You have to change the Vacuum Pump. It’s a known defect with tge 15/16 Models! I changed it, and solved the problem.

Well, wife was complaining about a hard pedal and Yuk not wanting to stop in traffic. Had to go into stealership for a recall ECU flash or something, but they confirmed it was the vacuum pump.

Would you happen to have a part number? Having a bit of trouble chasing this part down.

Thanks!!

Riklimoguy · January 3, 2019

1 hour ago, makorider said:

Well, wife was complaining about a hard pedal and Yuk not wanting to stop in traffic. Had to go into stealership for a recall ECU flash or something, but they confirmed it was the vacuum pump.

Would you happen to have a part number? Having a bit of trouble chasing this part down.

Thanks!!

Here you go bud! GM part Number 12669488

https://www.ebay.com/p/ACDelco-12669488-GM-Original-Equipment-Vacuum-Pump/2225458343?iid=163451535634&chn=ps&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-117182-37290-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fp%252FACDelco-12669488-GM-Original-Equipment-Vacuum-Pump%252F2225458343%253Fiid%253D163451535634%2526chn%253Dps%26itemid%3D163451535634%26targetid%3D593772336933%26device%3Dm%26adtype%3Dpla%26googleloc%3D9003610%26poi%3D%26campaignid%3D1661457327%26adgroupid%3D63612800546%26rlsatarget%3Dpla-593772336933%26abcId%3D1140466%26merchantid%3D6296724%26gclid%3DCj0KCQiA37HhBRC8ARIsAPWoO0yKeIMiTMWLb2Md-0DoazFdYubfIR8Fhs2hZm5V1TzfQc3XazSEiMgaAiRGEALw_wcB%26srcrot%3D711-117182-37290-0%26rvr_id%3D1804816863400%26rvr_ts%3D12612f801680ac197f80b2aeffbf0662

makorider · January 3, 2019

10 hours ago, Riklimoguy said:

Here you go bud! GM part Number 12669488

https://www.ebay.com/p/ACDelco-12669488-GM-Original-Equipment-Vacuum-Pump/2225458343?iid=163451535634&chn=ps&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F1%2F711-117182-37290-0%2F2%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fp%252FACDelco-12669488-GM-Original-Equipment-Vacuum-Pump%252F2225458343%253Fiid%253D163451535634%2526chn%253Dps%26itemid%3D163451535634%26targetid%3D593772336933%26device%3Dm%26adtype%3Dpla%26googleloc%3D9003610%26poi%3D%26campaignid%3D1661457327%26adgroupid%3D63612800546%26rlsatarget%3Dpla-593772336933%26abcId%3D1140466%26merchantid%3D6296724%26gclid%3DCj0KCQiA37HhBRC8ARIsAPWoO0yKeIMiTMWLb2Md-0DoazFdYubfIR8Fhs2hZm5V1TzfQc3XazSEiMgaAiRGEALw_wcB%26srcrot%3D711-117182-37290-0%26rvr_id%3D1804816863400%26rvr_ts%3D12612f801680ac197f80b2aeffbf0662

Thanks a bunch! That's what I thought it was but was not 100% on it.

I take it you've done it? How bad a job is it? With kids moving around constantly etc I havn't had a chance to even look under the hood and see what I'm in for.

Riklimoguy · January 4, 2019

Sure thing! I actually have a couple of them, being used for work (Limo). I had them both changed. Did not do it myself. My guys at the shop where I service them did them. I would assume a 45m job for a pro.

If you decide to do it yourself, make sure to disconnect the battery, otherwise it would trigger the ABS! As for the pump, it’s located on the left side, next to the steering column.

Good luck! ?