Pressure Drop in Water Pressure during HP Auto Cycle

[MEP001]

I will need to post a few pictures tonight, but i realized last night that my copper feed line is 3/4" which is reduced down to 3/8" for some reason...if i replumb everything with 3/4" pushlock hose will that help solve the problem? There is still a pressure issue, but will more volume mitigate the back pressure loss?

I don't think that will change anything at all. Your issue only happens with the auto drawing water. If it were a restriction problem to your pet wash it would only be a problem when the pet wash itself calls for more water than the line can deliver.