re bleed the system. you may need to have it pressure bled to rid the air. then you can see if you resolved the issue

Roy

Thanks, I will try pressure bleeding from the bottom up. Any better suggestions?

Is vehicle equipped with load sensing valve?

This 84 Toyota van LE does not have load sensing valve but it does have a equalizer valve for the front pads and for the rear drums.

A faulty equalizer valve can cause low pedal.

Check the rear brake shoes installation. Shoes have to be installed in the correct direction. Reversed installing of leading and trailing shoes can result in low pedal as well.

A vehicle this age could have the master cylinder replaced more than once and if a mistake made previously with an undersized master cylinder you would be never be able to solve the problem with a replacement sized as per the one on vehicle.

any way of checking the equalizer valve for proper operation?

Except for a pressure test, there is no other way.

Try this. Pull the e-brake and pump the brake pedal a few times. Wait a few seconds and test the pedal height again. If it improves, the rear brakes needs to be checked. Did you adjust the brake shoe to drum clearance?

OK I finally got the problem resolved. I pressure bleed the equalizer valve and that fixed the problem. Thanks very much for your assistance.

Glad to know you have fixed the problem.