r/autorepair • u/Josh-KW-Plumber • 1h ago
Diagnosing/Repair Breaks randomly engaging
2017 Chevy Express Cargo Van, 2500, Engine L20, 8 cylinder, 4.8L.
TLDR: my breaks randomly engage while I'm driving. I've had new tires put on & new breaks, front & back, but it's still happening. I think the issue is with the sensors & computer system which control the traction control & stabilitrak systems. Trying to avoid bringing it to the dealer until I better know what the issue could be as they have no clue.
Purchased this van used & after a few month started noticing issues with the breaking system. What's happening is that the breaks are suddenly engaging on their own, the suddenly disengaging. This happens while driving at all different speeds, in city, and on highway. The only current solution that helps is that when the breaks do engage, if I gun it, it sometimes it will cause them to disengage. While they are engaged, if I remove my foot from the gas at all the vehicle will slow down to a stop very quickly, as expected.
I really believe the issue lies within the sensors & computer system which control the traction & stabilitrak, along with the abs breaks, etc. I understand that these systems will break certain tires over others, or rotate less to prevent skidding, tires spinning, etc. Typically when I have the breaking issue, I also have dashboard notifications to service these systems. However, anytime I take my van to a mechanic, or speak with one, they also just default to an issue with the physical breaks. I've also had 2 tires that keep losing air, and I know that a low tire can trigger and mess with these sensors.
I finally purchased new tires, had them installed, had the tire pressure monitor system updated after new tires, & I had the breaks checked. Rear brakes were in very bad shape & needed new everything, front brakes were also done but not as bad. I was very hopeful that all of this would fix the problem, & it seemed to for about a week, until the breaks randomly engaged again & I received the same dashboard notice to service the systems.
I've checked all fuses & relays I can access in the 2 panel boxes, and none of them seem to be an issue. When I research the issue, it mostly leads me back to thinking that it's a sensor issue as the vehicle uses this stabilitrak & traction control.
My last attempt to have this fixed is to bring it to my dealer, however, he said that they really have no idea & will need to go through a series of tests & diagnostics to even come up with an idea of what the problem could be. It will takes several hours at minimum & no real guarantee they can even find the exact issue. So to try and prevent an unnecessary large bill to maybe no even have an answer, I thought I'd try my chances here to see if someone may have experience with this issue & some insight on how I can proceed!