>I worked in two air shops. Rebuilding the valves isn't too bad as long as the slide valves are good. At the time, all the ABD/ABDW slide valves were always sent across the Lapmaster.

To my knowledge this is standard. My friend sends his slide valve seat dressing stones to the Lapmaster between each use. Interestingly, Lapmaster's biggest market is Silicon Valley, or was, because they were used to removed the substrate from the chip matrices after the vapor deposition process.

>I maintain one loco with 14EL. This isn't too bad because the system is simple enough. The biggest issue is that the parts are just getting too worn, and no one is refurbishing the rings and bores. 6BL/BLC is similar and has the advantage of a self lapping independent.

I have some core prints, complete with [secret] dimensions.

>There are several issues with 24RL. First, I am convinced it was the result of an all night drunk fest at Wabco.

I like that (Walter V. Turner was probably rotating in his grave).

>(Actually not - it is an update of the 8ET/EL - maybe it was the drunk fest and 24RL was the hangover?)

After reading up on 8-ET/8-EL, I think it's the other way around. My friend says 8 is even worse to maintain than 24.

>26L is my favorite to run and repair

You go this right. I've heard from people in the industry that 24 (for pass cars) and 26 was the result of trying to cut down on the man-hours required for maintenance. U-12 valves have some ports in their slide valves, the sole purpose of which is to increase the friction between the slide valve and seat when the piston has moved part way.

>- but you have to understand it.

Let the air out of the pipe, and the brakes apply? ;>)

> 30 has even more variations and Wabco doesn't want any independent shop to have the test plates. I hate running desktop controls.

Royalties. At one time, about 15-20 years ago, WABCo was doing this for all test plates and test racks. I've hated desktop controls a lot longer than you have, nyaaa, nyaaa, nyaaa.

>Biggest problem with air brakes nowadays - hardly any engineer really understands the basic operating principles or physics behind it, and even fewer con repair or modify it.

Let the air out of the pipe, and the brakes apply. Simple -- haven't gotten it down to any fewer words. Physics?? It's the universal gas law, which is a combination of Charles's Law, Gay-Lussac's Law, and Boyle's Law (also throw in Avogadro's Law).

Right now it's dark, but it's neither cold nor raining. My keyboard works jut fine, so I had to resort to a brewski or three to have fun.