I'm not familiar with the ranger...
but i had many similar problems with the Kreepy Krauly

I could only see two solutions... either some sort of booster or turbo propeller added or switch to a new cleaner.

For the K.K., the additional propeller booster add-on, had been discontinued by the manufactor only one year prior. I could still " get one", but at high cost ( for what it is) & with no warrenty or return on it.

I got sick & tired of babysitting my K.K.... it seem to get re-stuck every ten minutes or so of cleaning & I was worried about leaves/sticks clogging up my line somewhere.
I decided to go automated ( robotic) instead.

I love my Dolphin robotic cleaner!
I didn't even buy a ( recommended) drain ramp & it works fantabulous!
( I really do like the remote feature too, although I am seriously considering adding some servos to it for better "driving"...lol)