How to replace a compressor for a water pump?

[Trunkhill1]

Nicely done. Is that a newer tank? The clean welds and no rust sort of looks like it is much newer than the coach.

No, the ends of the tank had burst even though I thought I had all the water drained last winter.  I had a friend weld them back together.
So I learned to leave the valves open even though "all" the water is drained out of the system.

[Trunkhill1]

Nicely done. Is that a newer tank? The clean welds and no rust sort of looks like it is much newer than the coach.

Here's the pics of what happened this last spring...

[Trunkhill1]

So one important note for my water system, especially since I replaced the air compressor for a water pump.  I used braided washing machine line to replace all the copper lines due to multiple leaks; if anyone else does this ensure to remove any in-line mesh-screens within the ends of the washing machine lines themselves!  The washing machine lines may have extremely fine miniature mesh push-in screens which will trap rust/debris in the tanks/lines and give one no end in frustration when you try to prime the system a few months later!
Needless to say Occam's razor came into play after a few days troubleshooting as I was moving and replacing the pushbutton actuator switch for the water system from the fuse panel to a new rocker-switch nearer the sink and shower...  The results were a great improvement however.
Cheers!

[CapnDirk]

Real nice, and thank you for contributing back for those in the future. 
I may have missed it, but how did you address the vent issue?

[Trunkhill1]

Real nice, and thank you for contributing back for those in the future. 
I may have missed it, but how did you address the vent issue?

I took the brass T off the end of the tank and replaced it with a simple elbow.  The petcock under the trailer provides the venting for fill and use.  See the before/after pics.
Cheers!