So I garbage picked this what looks to be near new Karcher 2400 powerwasher. Had trouble with engine which i fixed. Hooked it all up to water, fired it up and it doesn't keep good consistent pressure. Took the unloader out and it looks real clean. My question is about the hose. Everything seems to screw on fine but on one end the hose is still loose in the coupling (i can wiggle the end around when coupling is tight) and leaks like a sieve. The o-rings and threads seem fine and I can't tighten the coupling any tighter. I assume it's not suppose to leak like this. Do i need a new hose/hose ends?

Thanks,