Something is routed wrong then. Air from the compressor goes to the tanks under the bed. Then air is let into the airpack when you develop enough brake hydraulic pressure to cause a valve to open. That pressurized air pushes on a piston which adds to the hydraulic pressure of the brakes. When that air is used, it is vented to the air filter housing.
That is pretty much all the compressed air system does on the truck. If you are getter pressurized air to the engine. Then, something is routed wrong or you have the fording kit installed and one of the valves is open.
Hydroboost is the brake power booster driven by the power steering pump.
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