I'm flummoxed with a Delta, mid-1990's mixing valve.
The valve has shut-off's via screw and locknut on cold and hot inlets, and I have good pressure there at both hot and cold side.

But an inch-or-so away, at the main body holding the cartridge (I don't know the terminology, sorry), no cold water at all - zero. Hot is fine.

Between the shut-off screw and the cartridge area there is a cylinder-shaped area, perpendicular to water flow, on cold side only. I can't find any "user-serviceable" part, a screw, nut, rotating device, anything.

I need help from a pro,

Thanks!

Marty

Sounds like a balancing spool. It has probably failed. Now to figure out how to remove it. Kissler & Co., Inc. : For all of your plumbing repair parts needs