Had to replace a hpop cannot get pressure from it. Took the plate off and turned the motor but no oil out of the top of the hpop. Crank it until the low pressure comes up and then oil will slowly ooze out of the hpop. But no pressure!
Should there not be a lot of pressure straight out of the hpop? Or is it possible that I got a bad rebuilt pump?

Thanks

 

it has to be a closed system to build pressure. it normally takes a lot of cranking to get it to build the 500 psi of pressure to fire it up the first time, it has to bleed all the air out of the system before it will fire off. It is best to have a good battery charger on it or even another car or truck with jumper cables hooked up to it, it will kill the best batteries made before it will start after doing a HPOP. don't crank for more then 10seconds at a time, and wait a minute before cranking again to save the starter. if you have a late 04 or later truck then you can pull the ICP sensor and crank it over till oil comes out of it then reinstall the ICP and crank it over, this just helps prime the system a little quicker.