Will do that when daylight comes (and my shift ends )

The suns shining brightly right here. Where are you, the other end of the world?

Look at my location

I knew that. Was just screwin' with ya!! LOL.

fck, that nightshift is really getting to me, hehe

Got around to checking that hose.
No change in idle when hose pinched off (as good as that went), no change in idle with carb/throtle body cleaner spray over the check valve....or around the throttle body (took to opportunity to spray around the engine bay while I was at it)

Is that giving me any clues?

Not a vacuum leak then.

Did you bleed the master cylinder at the fittings?

Yep, bled it with the little tubes provided, pumped it til no further bubbles in tubes....and then a few times more.
All done on the bench before installing.

Hmmm. Try bleeding the master by cracking the fittings on it's side.

Thats gonna be difficult with one person, since I cant put a one-man-bleeder in the side as there are no bleeder 'valves', so big chance it will suck more air in than there might be coming out...and the MC was already really thoroughly bled before installation...

Nobody to help? A town drunk, even?

Not always true... had an 86 Z-28 booster went had no pedal stiffness at all went to floor nice and easy. spooky stuff scrambling for the E-brake in traffic.

Make sure your calipers are not on the wrong side

well, there is this dog...

yeah, but that's a Z...hehe. And swapping my master cylinder which I thought was the culprit didnt change anything. Could double check and send the new one back for another new one.
When I pump the pedal with engine off, it becomes nice and solid in 2-3 pumps, making me believe the booster and check valve are in ok condition.

They 're good, bleeders are on top not the bottom. But thanks.


Just for completeness, took the rear drums off and inspected. No leakage from cylinders, shoes not worn. Adjusted again a little (done two weeks prior to all this) and took a stethoscope to the brake pedal area to make sure the squishy sounds did indeed come from the booster area.