Aster GWR Castle short of steam

[Moonraker]

My Aster Castle was running well but then there was a period of about nine months when I did no run it. Then, when I did steam it, the loco built up pressure okay and the safety valve blew off but it would not run and the pressure did not last.
Today we disconnected the tender, put the loco on rollers and connected an air-line to the water feed. Boiler pressure went up to 2 bar and the wheels rotated just fine. Then, with the regulator and blower both shut completely off, we noted that there was a small jet of air coming up the blast pipe and the wheels were juddering a little.
My diagnosis is that the regulator is leaking a little. Am I correct? Am I also correct in thinking that there should be no steam flow at all when the regulator is shut? If so then what is the best way of fixing the leak?

Regards
Peter

 

[Neil Robinson]

Peter,
It would seem that, as you suggest, the regulator valve isn't shutting off completely. However I don't think that's the problem. I presume any steam leaking through the regulator would pass to the cylinders and assist with motion rather than prevent it.
Some possible causes could be a leak in the steam pipe between regulator and cylinders, badly trimmed wicks (presuming alcohol firing) or the bypass valve stuck in the closed position.