Letter from GM on 2017 Denali

[Blackcar]

Got letter from GM today on my Denaili dealing with increased braking effort ,hard pedal,and or potentially increased stopping distance.Something about engine mounted mechanical vacum pump output. Also says not following recommended oil change intervals could contribute to condition.They extended warranty 6yr or 72,000 miles

 

[Tonyrodz]

Got letter from GM today on my Denaili dealing with increased braking effort ,hard pedal,and or potentially increased stopping distance.Something about engine mounted mechanical vacum pump output. Also says not following recommended oil change intervals could contribute to condition.They extended warranty 6yr or 72,000 miles

Oil change intervals affect breaking? What do they recommend and what are YOUR intervals?

 

[Blackcar]

Doesn't recommend oil change intervals just what the owners service interval is which should be what DIC says

 

[greenhornet]

The Vac. is driven off of the engine so it uses the same lubricating oil,so good clean oil may prolong the vac. pump.

 

[Doubeleive]

the vacuum pumps have been failing that is why they are extending the warranty (it is a known issue), I would imagine this is there way of skirting around a full recall.
I think something happens to a seal and then oil gets inside and that's why it takes increased braking pressure

 

[Rdr854]

What years and motors does this affect?

 

[Doubeleive]

What years and motors does this affect?

15+, Not sure if they changed anything on the late model trucks, like a different supplier or revision, etc it's been brought up the forum before. I think something happens to a seal and then oil gets inside and that's what causes the need for increased braking pressure

 

[Blueinterceptor]

I got one too

 

[malones99]

Got one for my 15 Tahoe.

 

[mck024]

I didn't get a letter, but the warranty tracker on my.chevrolet.com indicates my 16 Suburban has:
Special Coverage N182202780
Expiration mileage 72,000

This explains it:
https://www.gm-trucks.com/forums/topic/222496-gm-stepping-up-on-brake-issue/