I'm missing the pipe between the UIM and the brake booster. I understand it's supposed to have a one way valve in there. Does anyone know the Mazda part number for a replacement, or a good alternative?
It does deffo have a check valve in it, give it a squeeze in the middle lol
From memory I actually though the same and just put vac hose on, then wondered why I had 0 brake assitance after a pull (it keeps the vacuum in the booster)