On May 14, 4:38 am, wrote:
How does the trigger feed back to the machine? I mean, I know it does,
but I just don't see how. Does the pump need back pressure to go high?

There should be a relief valve. It may be stuck.

http://shoppingcart.msservicecompany...product_files/...

Thanks for the parts link!

Is the relief valve in the trigger mechanism?