How do I check for a clogged fuel filter van makes load squeal then stalls?

Clogged filter will not cause a 'squeal' , maybe check belt(s) and driven components for problems? Does the squeal and stall happen when A/C kicks on?

Fuel filter should be a very inexspensive part just replace it and go from there

The camshaft synchronizers sometimes fail, and cause both squealing noises and stalling issues. You can try removing the cam position sensor on top, then lubricate the shaft of the cam synchronizer with several drops of synthetic motor oil or gear oil applied with an oil squirt can or large syringe.