How Important Are Oil Changes to Brake System Performance?

By Tom Rayk, Director of Training, AVI

Many shops service brakes on the popular line of GM vehicles that may be part of an NHTSA campaign numbered 19v645 and 20v603. This campaign centers on the improper operation of the belt driven pump that supplies vacuum to the brake booster. This can result in a high hard brake pedal, and will increase stopping distances. With various newer technology that allows for lower emissions and better fuel economy, the engine does not always supply enough vacuum, which is why we have a belt driven pump. The vacuum booster has been a standard for allowing great brake performance for many years, however, requires the proper amount of supply vacuum to function as intended.

The campaign to repair this issue involves an update to the software which allows the ABS pump to supply added brake boost at lower speeds to where the concerns are showing up. If the update works as intended, the brakes should perform as needed.

Now let’s get to the original concern. Like any part, a vacuum pump can fail after years of service. The belt driven vacuum pump GM is using is lubricated by engine oil and has a pick-up screen to prevent debris from damaging the pump. So, if the following service issues are encountered the pump can fail:

• Improper oil change mileage
• Use of non-approved oil
• Engine coolant system issues
• Improper engine warmup operation

In some cases, the pandemic has caused lapses in proper vehicle service. So as a professional repair facility you should always ensure the software update has been done. Along with the proper brake inspection, you should always validate the vacuum pump operation and always inspect to validate there is no oil build up in the vacuum line or in the booster. Oil in these brake components can cause other issue as to brake operation.