After spending another two hours working on our sophisticated single handle kitchen faucet, I threw in the towel and bought this simpler and far more reliable alternative solution.
It took me only an hour and five minutes to install this faucet and that included rounding up tools and a caulking gun.
I had spent more then 10 hours trying to repair the old faucet including time on the phone with two suppliers. During that time, I tied up other people for another hour at least. The product complexity cost us all more than we expected. Furthermore, there were at least three different variations on the old product and each required different parts to repair them. I don't think I had the right parts I needed.
This was a clear case where product complexity produced a great looking product (Moen 7430) that was costly and difficult to repair.
The new two handled faucet(Peerless P999575-SS)has a side spray and has smooth acting ceramic valves and cost less than half what the single handled faucet did. It has nine parts compared to the 26 parts of the single handle faucet.
Most importantly, each of the operating parts performs a single function: Each faucet operates independently and controls the flow of water. The spout directs water and has no interaction with any of the other parts of the faucet. The side sprayer sprays water with no fancy diverter logic. Any one piece can fail without requiring the replacement of other pieces and this is typical of high reliability design.
Any design in which mechanisms perform multiple functions is promoting novelty over reliability. This is fine for products with a short life, but a real pain when applied to products that have to be repaired many times over their useful life. Simplify your life with appliances and household products designed for reliability
Thanks to Zack and to Glenn for suggesting a switch to a simpler model.