Took the hydroboost apart and replaced the seals with a rebuild kit to get rid of a leak. Put everything back together and reinstalled it in the car. When turning on the engine, and bleeding the air out the system, the break pedal would self apply almost completely. Applying the gas would make the brake pedal go down further. Turning the wheel lets the brake go up a little.
There appears to be an excess of pressure. Reading about it, people often say the dump valve was likely not seated correctly. Not sure where fluid goes when it goes past the dump valve, I took the hydroboost apart again to flip the dump valve over and reinstalled it only to find the same problems.
Is there anything else that could be causing this issue? I noticed when taking it apart the first time, there were some grooves on the spool valve where o-rings would be, but I don't remember seeing any the first time taking it apart, so I left it without o-rings. Could that be causing the issue?
Here is the diagram on the instructions that came with the rebuild kit: