If you are talking about the brake pedal then your problem is much bigger. Base on the description you are giving and the fact been a Silverado, I will say the master cylinder is leaking. The brake booster is sucking in the oil and filling up causing it to leak at the booster rod where the brake pedal attaches too.
If that is the case you will need to replace the master cylinder and the brake booster. If you let it go too long the calipers will get stuck closed causing a drag on your truck or not to move.
Let us know if that is the case so it will help others.
Friday, May 19th, 2017 AT 10:19 PM