Here's a diagram of the air pump circuit. The two check valves route the vacuum when pump is on and off. The vacuum relief valve controls the amount of vacuum when in cruise and idle, takes the place of the pcv valve I used this valve but in reverse.
https://www.mcmaster.com/valves/valv...and-inert-gas/. I have it set to 5 HG at idle. I bought the vacuum relief valve at mcmaster carr. The large check valve is just a common smog pump valve
https://www.ebay.com/itm/25457608737...05db55fbb4581b The small check valve is just a cheap 3/8 plastic piece.
https://www.usplastic.com/catalog/it...x?itemid=36843