700r4 will not downshift

[Tolle]

Hi guys, one of my buddies owns a 67 corvette 427 cu, 425 hp. with a 700hr4 reinforced bought  from the USA it lasted 2 yrs.,his fault, then toast.my friend now chose to have it rebuilt in denmark , and at first off performed well, next day awful, day after on next drive ,  it will not downshift at all, even with a hard kick? What should we be looking for, too long cable , too short cable
sticky TV valve ? In idle the pressure is 75 psi, and ATF. temp is 140F at normal working temp.It has the correct adapter plate for a edelbrock carb
Any suggegtions ,Tolle Denmark

[Crosley.In.AZ]

Need to check for pressure increase as the TV cable is pulled.  You can do this while in park , engine at idle.  pressure should increase as the TV cable is pulled out.

TV cable should be at FULL pull with the  throttle at WOT.

No pressure increase means the inner TV valves are stuck

[Tolle]

Need to check for pressure increase as the TV cable is pulled.  You can do this while in park , engine at idle.  pressure should increase as the TV cable is pulled out.

TV cable should be at FULL pull with the  throttle at WOT.

No pressure increase means the inner TV valves are stuck