Pump wont pump water

Is there any filters screens in the incomming water supply hose thet may be partially clogged?
Is there a water box on that machine that may not be filling up? Bad float or something?
Something may be stuck in the pressure regulator(front of machine) bypassing water and not building pressure,

There should be awater box on the back of the machine. Make sure it is filling up with water like Kevin suggested.

Either your check valves are fried or your regulator is not plumbed right. Are you certain your regulator is plumbed right?

If there was a plug on the pressure side of the regulator the bypass would create more pressure in the manifold and water would be shooting out. It looks like the bypass goes to the manifold because I can see a glimps of it. Also if there was a plug on the bypass side the pressure side would also create more pressure.
And I can hear your valves on the engine chattering like crazy. You definately have something wrong with your valve train.
Also Batista, the video really doesn't help because your not telling or showing vital things to properly help you. I would need to check all the hoses to see if its all plumbed right, use a secondary pressure gauge etc... Something may not be plumbed right or your regulator is missing parts.

Did the pump loose its prime? Have you noticed a slow decrease of pressure over time?

Also pull your pressure line fittings and check for water scale buildup. Your pump may be creating pressure yet it is not getting to your wand due to a blockage.

Your check valves are bad.

There are three on the high pressure side and three on the low pressure side of your water pump manifold. Use a ratchet and pop off those plugs to have a look see. Sometimes the orings wear or the disc in the valve(s) get hung up on the plastic. Often an o-ring may look good but is actually worn. And same goes for the valves.

I was also thinking that if "you have a bypass manifold "with an oriface missing, you will experience the same symptoms. But pressure will not show higher a few hundred psi. In the video I cant recall anyone turning the regulator to show us that end?

No I dont mean the pistons. I mean the check valves. Remove the 3 large caps on top and the 3 large caps on the lower part of the manifold. I think you need to take this truckmount to someone that knows what they are doing. Take it to a pressure washing store.

Those are the check valves. Pull them out with a needle nose pliers or pick and inspect them along with the manifold.
Also, I barely saw you increase the pressure. Once the gauge reads zero there is no need to turn it counterclockwise any further. You should have shown us what it does when you turn it clockwise a little more. So we can see what happens.
try putting a tool on the end with a tip also because that female QD is a ghetto way to initiate flow.

He wants you to have some resistance on the system discharge when you initiate the flow. Try a wand..or another tool on it instead of an QD.

Taking off the manifold was unnecessary. I never said to do that. Unless water was leaking you created more work for yourself. You are on your own now!