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Q: Brake Booster

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So I cleaned my throttle body because my RPMs were fluctuating like crazy, especially while idling in park. Cleaned it with carb cleaner and that fixed a multitude of other problems I was having as well. Truck runs great, aside from a connector breaking leading from the throttle body to god knows where, but I replaced the hose connector. Bad news, the stiffness in my brake pedal has changed. I am able to pump my brakes and get the brake pedal firm while the truck is shut off, but when I turn it on the pedal sinks to a set spot (does not continue sinking) and I can vividly hear the air as I try to pump the brakes. I drove it around and am able to stop, but am worried if I have to stop suddenly I wont be able to respond as quick as I should. Keep in mind, I did not have this issue prior to cleaning the throttle body.

My car has 185000 miles.
My car has an automatic transmission.

I think the reason the truck was running rough was the broken vacuum connection and it went to the brake booster. You may have only had partial vacuum to the brake booster before, and now have full assist. You should make sure to have a mechanic road test the brakes to make sure they are operating normally. Have a certified expert, such as one from YourMechanic, inspect your brake system in order to guide you on any repairs or adjustments that may be needed to get your brakes functioning as they should.

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