If your machine's pump has individual hex head caps over each piston section, remove the caps and remove each of the spring-loaded one way valves just below the cap. One or more of them is stuck open with a small piece of debris. The most common cause of this is removal of the inlet screen where your garden hose hooks up to the pump. Even if the screen hasn't been removed, a bit of scale inside may have worked loose and is holding one of the valves off of its seat.

Below is a picture of a typical pump....the sprind loaded valves are located just beneath the 3 large hex caps facing the front, and also the 3 large caps on top. remove the valves one at a time with a needle nose pliers and make sure they're free. Doing them one at a time will allow you to keep the parts straight. The pumps aren't complicated, but I've seen more that one come in for repair with all of the valves put back in upside down. If you keep track of everything and are sure you'll get things back together in the proper orientation, it's a good idea to have the garden hose hooked up so you can turn the water on and flush the pump out with the valves/caps removed.

Your pump may be different, so search online for a breakdown before disassembling it if it does look different than this one:

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I don't have that type of pump. So to get to the piston to clean them out it look like I'm cracking it apart.
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I found a broken O-ring in one of the check valves which also worked its way into the seal seats below the pistons. The odd thing is I can not find where the O-ring came from. As for the vibration it's gone. thank for the help.