Problem with Baracuda Ranger

I'll start with my setup. The pool is 18' X 48" AG, Hayward 1.5hp pump, & Hayward s-180T sand filter. I bought the Ranger last season and it worked great. This season it will run for 1-2 minutes than stop moving, the pump will get an air pocket and quit pumping. When the pump is running without the vacuum the pressure gauge on the filter reads 12, with the vacuum connected it drops to 2. My pool chemistry is great using the BBB method that I learned here last season. My water temp is 72-78 degrees. I did have a lot of water bugs last season before finding this forum, and the sand has not been changed since then (it is 1 year old). I have checked the hoses and there are no cracks or holes, I've disassembled the unit and there is nothing wrong with the diaphragm, and I've tried all three positions on the valve, but still the same. I thought there was just too much dirt in the pool, so I cleaned it out with the manual pool vacuum, but still the same thing with the Ranger. I have disassembled the pump and it is like new. Tomorrow I will try replacing the sand, but after that I'm out of ideas. Any suggestions would be greatly appreciated.

Thanks, Chas

I cannot help with your fix, but I can tell you that you do not need to change your sand. Sand lasts a LONG time. I am on my 11th season with mine and there are others who have had their same sand for much longer than that. Hopefully someone will pop on here and offer you some ideas about getting your unit to work. Good luck and welcome. We appreciate you becoming a subscriber!

BTW -- That is an awfully big pump for a pool of this size. I doubt that is the reason for your problem but I'll let someone offer their opinion.

Ninth season with my sand! I suspect something is wrong with the Ranger. Not familiar with that cleaner, but frequently any moving parts can get deposits on them from drying water (I had to trash a washing machine that sat too long and the silt hardened)

Carl