Hopefully this is an easy one to solve!
This year, when trying to vacuum my pool with my manual vac, when I use my Hayward Skim Vac adapter (the circular plate that covers the skimmer basket), very shortly after it starts pulling water, I get a massive air bubble come back through the skimmer, which causes the plate to pop off and the pump looses prime. Even if I reconnect and wait, it repeats all over. Tried holding down the plate too but no luck. I prime the vac hose as much as I can but will get some air as I transfer it to the skimmer.
I had switched the orientation of the hose (neither end rotates and both are glued to the hose) when first trying to vacuum, and switched them back with no change. I have since reversed it again and replaced one end with a new screw-on type (because I noticed the old one was cracked) but still I cannot use the skim vac adapter. I've checked the adapter and don't see any cracks in it.
If I plug the hose directly into the bottom of the skimmer, it works 100%.
The hose is old, but I don't see any cracks. Trying to do as much cost saving troubleshooting before taking the dive and buying a new hose (not sure that will fix anything).