Pressure reducer came apart - Hitachi EC119SA Twin-Stack Air Compressor with Control Panel and Couplers

Pull it apart and see if the flow restrictor is plugged in the water inlet to the shower head.

Take the valve apart and make sure the seal on coil is not damaged have also seen the snap ring come off

What is your question? You need to give more information such as what tool brand and model you are using and what problem you are having. When I read "reduce pressure" all I can think of is using a pressure regulator with an air compressor. They have a gauge and a dial that use turn left or right to raise or reduce the pressure coming from the compressor.

Modern low flow plumbing devices reduce water flow by using smaller passages inside the unit. The downside of this conservation is that appliances are more easily clogged by debris that may be in the supply lines. Frequently it gets stuck in the cartridge. I have even found it in the supply line connections.

Take it apart, just watch for the springs and valve falling out. Regulators aren't complicated and if you can save $40 for ten minutes' worth of disassembly, cleaning and reassembly then you're probably ahead.

If nothing else, you get to see exactly how it works, and that's worth something too.

lp

Pressure regulator can be dis-assembled and lubricated or replaced. If lip seal and pressure pin are dry, the regulator will not function correctly. I do not think that there is a repair kit but try lubing with silicone paste sold at Lowes in the plumbing department. Lowes also stocks campbell hausfeld regulators and water seperators. An upgraded regulator will provide more cfm and a greater accuracy in pressure control. To repair regulator, empty tank of air and turn regulator counter clockwise to release pressure on spring and take apart. If you do not see any way to dis-assemble, then there is a tiny pin on the lower edge of knob that must be removed before knob will thread off completely. Push pin up from under knob. Good luck

i like to use air pressure through a blow gun with a fine tip to get into washer hose,but reduce air pressure as not to blow hose apart.