Brake hoses? Are they becoming restricted.
The purpose of the dish washer is to break the surface tension between the piston and the seal in order to allow fluid to flow into the main cylinder before the piston is fully home. But when would that happen? The spring is always compressed against the seal, so a vacuum is needed in order to deform the seal enough to allow fluid to flow, But again when would that happen? If it's to compensate for lowering temperature, the main port would allow fluid to flow from the reservoir to compensate for any contraction. It's not all that critical how that spring washer goes in, if it is needed at all. It will break the surface tension either way. If it was a pump, I can see the value, so it's only use may be when the system is being filled and bled, and pumps the fluid into the system. During that process when the bleeder is closed, the system will be at zero pressure, then the pedal is released with the bleeders closed and a vacuum will be created during the return stroke and it would be desirable to replace that vacuum with fluid.