I have installed a M/C from a 77 malibu, manual /disk 6 cyl application and all the disk stuff up front and cant get rid of the spongy pedal.All parts are new.
It feels like the front brakes are barely working.
I have used the correct rod hole for manual app.
Horribly spongy but have bleed system and get no air!
I then plugged the front line output port at the master and the pedal is then hard as rock so I know the master is good.
I was told I could use the stock 71 drum/drum combo valve with this set up. Is this good info?

What is a presure gauge at the caliper supose to read on a good working system?
Any info appreciated!
Thanks.

Who ever told you drum/drum proportion block is ok is wrong.

YOu need the combi valve for drum/disc from 70-72,

Check with www.mpbrakes.com (http://www.mpbrakes.com) for new.

I agree w/ DG , sounds to me like a prop valve problem. once you get the correct valve, I would pressure bleed it to make sure all air is out.

Thanks all! Will order one tommorow.
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