If you started the line nut by hand two or three revolutions first, before using a wrench, the nut is not cross-threaded. If it was cross-threaded, you would have had to tug pretty hard on the wrench all the way.
The nuts are soft metal, but they usually go into an aluminum fitting. The threads in the fitting are the first to become chewed up. If you remove the nut and it had been cross-threaded, you all see long, thin, silver metal chips in the nut's threads. At that point you can try to reinstall the line, but the better alternative is to unscrew that fitting from the old pump, and use it in the new one.
There is an o-ring on each end of the pressure hose. Those are supposed to be replaced each time the hose is reinstalled. That o-ring is a better suspect than a cross-threaded fitting. Most replacement hoses and pumps come with the new o-rings when they are called for.
Jan 18, 2021 at 9:43 AM
(Merged)