I will sort it all one dayLOL

I have a quickie about the check valve.

I have 280ZX front brakes with a 280ZX booster and master cyl on my 240Z legs...

If I use the check valve the way it supposed to, the brakes are very firm and not too powerful. If I reverse it, the brakes are quite strong but the pedal travel is enormous

Any thoughts?

Check the adjustment of the rear brakes. What rear brakes do you have? Proportioning valve? Remember that the 280ZX was setup for rear discs.

Edited February 27, 200916 yr by sblake01

I have std 1972 rear drums. I have fitted an adjusting prop valve at the rear for a later rear discs conversion. How is it related to the check valve ?

I didn't mention the check valve. I was basically saying that your rear brake adjustment has an effect on pedal travel. The closer the shoes are to the drums, the less distance the pedal will have to travel.

Oh I see. Yet the pedal travel is long only if I reverse the valve-check

Well that is confusing to me also because the check valve is there to hold vacuum in the booster and reversing it would allow the vacuum to escape. The problem might be in the booster itself.

Are we sure the diagram for the fitting of the check-valve is correct in the Haynes? It would not be it's first error!

May a knowledgeable person check, please?

I don't know what the Haynes manual says because I don't use it. The end of the check valve that you can pull vacuum through goes towards the engine, the end you can't pull vacuum through goes towards the Master Vac. If you can pull vacuum through both ends it needs to be replaced.

Correct on the valve function, well stated.