Suggestion to your best judgement. If no troubles with it yet, keep driving. These systems are a closed up loop of sorts and never need any opening if no troubles occur. The mfg'r manual recommends the changes of (x) miles to get your vehicle back into the dealers garage to clean out you unsuspecting wallet!
Please believe me! This is absolutely a true statement. Call it a scere tactic!.
The engineers of today, if the parts they designed are in good condition and operating properly, they have done a good job to ensure reliability built into your vehicle.
The rest is hype! The dealers and mechanical sales people project a negitive question: maybe,or what if, type of a situation.
I could also go so far as saying "LIES" are being told to you and if you fall for the scare tactics (lies) being told to you by the service managers, you will be a victim of false situations, dreamed up to make you suspicious of a problem that does not exist in the vehicle, oh! maybe this or maybe that will soon happen
now in your mind because that is how the service department in almost all dealerships and national and local repair shops do business. They Get You Worried !
So,Drive ! IF IT AIN'T BROKE, DON'T TRY TO FIX IT !