I purchased my S4 used, it came with these purple DV's. After some searching it looks like it could be some form of a hyperboost dv, but not sure which model. Can anyone shed some light on what I have?



Thanks for the help

 

Those are the old Hyperboost DVs.

They are the non-adjustable ones.

 

Do they have a high fail rate? Anything I should be concerned about? Is there a good way to tell when they are failing?

 

They are a lifetime valve.

They are rebuilable and cleanable. Just take them out and unscrew the vacuum port lid.

You may need to change o-ring seals eventually.

I clean mine and re-lube them every other oil change.