Replaced shallow well pipes and put in pitless adapter: Now no water pumped

I replaced my existing 50+ year old galvanized pipe leading to my shallow well with sch 80 1.25 inch PVC. Total horizontal run is 20 feet. I also replaced the well seal with a pitless adapter, attaching that to a sch 80 1.25 inch PVC down pipe. The down pipe is about 20 feet deep, terminated with a Merrill foot valve (with screen) to add another 5 inches.

Nothing inside the house has changed. Same 2 year old, shallow well jet pump. The new horizontal pipe slopes up to the pump, with one 90 degree elbow and one union before connecting to the pump. The pump has worked OK up to now.

The old drop pipe was flexible tubing, and it measured right at 21 feet to the end of the foot valve. I measured the bottom of the well at about 21 feet as well, using a rope with a weight. The water level was about 7 feet above the bottom of the well. So, I thought I would be good with a new drop pipe of about 20 ft 5 inches.

When I first tried the new piping, priming the pump as usual, the well produced a resonable flow for about 20 seconds, but the water pumped had an orange brown color. The old system pumped very clear water. But as I continued to run the pump, the flow diminished to nothing. I thought I had lost prime, and continued to prime the pump for quite a while. This time, very little flow was produced. I suspected that I had a leak in the suction side, so I capped the pump output, and ran my air compressor to the jet assembly access port. I ran the pressure up to 50 psi, and the system held that with no problems. So, I don't think I have a leak in the suction side. I thought I might have a blockage in the jet nozzle, so I disassembled that and ran a small rod through it. No clog. I left the output of the pump plugged, and filled the prime port up, and very briefly turned on the pump. It immediately pumped up to 40 psi on the output side. So, I don't think I have a jet or pump problem.

That pretty much only leaves the drop pipe to be checked. Am I on the right track here? Did I miss something else to check? Any suggestions on how to check for a clogged foot valve, short of pulling out the drop pipe?

Thanks for any and all help.

After pumping orange stuff, I would certainly check the foot valve. While you have it out, and especially if the foot valve is not clogged, I would work on the pitless adapter. Silicone the o-ring before you set it in the well. Then let the silicone dry before you start the pump. Some pitless adapters have o-rings that need pressure to seal, and will let air in under a vacuum.

Thanks Valveman. I pulled the footvalve, and NO mud, sediment, etc. I am now suspecting the pitless adapter as well. When you say silicone the o-ring, do you mean to use silcone caulk (sealer) around the o-ring? I only used the recommended silicone based anti-seize / gasket lube from Merrill.

Yeah caulk. You gotta use the kind that sets up and hardens somewhat.

Thanks. Just so I am clear, I apply silicone sealer around the o-ring, then lower it into the casing? Assuming I bump the o-ring on the casing a little on the way down, some of the sealer will be lost. So, I assume that I don't need a real thick layer for this to seal.