Hi,
Double-check to make sure all fittings are tight and not allowing air to enter. If they are and there are no air bubbles in the reservoir, we have one of two ways to go.
First, they do make products to eliminate pump whining noise. You could try that to see if it helps. If it doesn't and there is no air, then the pump is the likely issue.
I attached a pic of a product below, so you know what I'm referring to. That pic is from Amazon, but most parts stores would have it.
Please understand, I can't guarantee this will resolve the issue, but it is an inexpensive way to try before replacing the pump.
Let me know.
Joe
See pic below.
Image (Click to make bigger)
Friday, November 17th, 2023 AT 9:26 PM