NC hard brake pedal

[Custardtart]

So having just changed the fluid and pads, done a full bleed, double checked no leaks, lubed the caliper sliding pins etc etc I have a hard brake pedal.

With ignition on when I first press the pedal I have normal travel but if I press it again it gets firmer and the 3rd time it goes solid.

If I pump the pedal before turning on the ignition, the pedal goes hard and then stays hard when the ignition is turned on.

If I leave it for a few minutes it returns to normal for the first press.

I'm thinking it's the vacuum check valve inside the pipe coming out of the brake servo that's faulty? Any ideas other than that? Is there a way to test for leaks in the vacuum system?

I've got a replacement pipe with the check valve inside on order but Mazda Aus are their usual useless self and it's on 4-6 weeks back-order from Japan so I've sourced a used one til it arrives.

I've also got a used brake servo and reservoir coming from ebay as it only cost $50 and I'm trying to get everything sorted before the 13th July track session.

[RS2000]

Could be the check valve is stuck in the closed position, or a leak in the hose.
Spray carby/throttle body cleaner along the hose, & you'll soon tell if the engine is sucking any.

[Custardtart]

Quick update, i changed the hose with the check valve and looks like it’s all fixed now.