Dewalt DP2800 pressure washer

I have a DP2800 that is a couple years old.  I had it in the back of my truck and it accidentally flipped over.  I refilled the oil resivour, but nothing else.  I can’t get the pressure washer to preesurize when I turn it on.  It’s moving water through the machine, but nothing else.

There is a red cap on what looks like a resivour on the top, but I’m not sure what this is for.

Any ideas on what I need to do to get it working?  I no longer have the user manual to look at this.

Thanks.

I like to attack the obvious first, then go from there. Are you using the soap tip?

I have the 2600psi Model, my camera battery is dead. I’ll post a few pictures up shortly. The red cap goes on your CAT pump. It’s where you fill your pump oil. Just below the red cap you should see a round plastic clear window with a red dot in the middle. That show’s you where your pump oil level should be. If it’s below the red dot, you may cause damage to your pump.