Hello Scotty, I have a 2015 Jeep wangler JK sport with around 60,000 miles. We have been noticing an issue with braking power that I have never experienced in any car before. On a cold start, right after startup if the car is placed in drive or reverse (automatic), once the car gets up over 3mph I am unable to apply a full brake application. The brake pedal is firm and I stomp on it with both feet without it going to the floor, but it is not applying a full brake application and I roll to a stop (well past where I would normally). This only happens on the first brake application after startup of a cold engine. If I pump the brake a couple times before moving I have full stoping power and now problems. Brake pads are good. Front rotors are good, rear rotors are a bit pitted but not bad. Master Cylinder reservoir has the appropriate amount of brake fluid. No discernible leaks. A friend suggested it may be the brake Booster losing vacuum. How do I check this and is it fixable or do I just replace the booster?
It could be a vacuum leak at the booster but also could be a leak in a brake line, master cylinder or wheel caliper sucking air into the brake lines when parked over time. You should have it checked ASAP by a professional.
