I was asked by some friends for some suggestions. They have a caboose that they need to ship off the property, but it is failing the air test. It sets up fine in Emergency, but it won't do a Service Application. They've changed out both the Service and Emergency portions, and even the bracket assembly so I've been told. Still no go. I do not know off hand which version of the AB brakes it has.

My only suggestions so far is they have the gasket in backwards or to change out the service portion again. Can anybody else suggest another possible problem?

Greg

Since it works in emergency that side of the reservoir is charging. Do we know if the service side is charging?

Simple things to look for include routinely cleaning the dirt trap assembly. As well, there are some small brass dirt screens which may be blocked or missing in some of the bracket ports, as I recall. Usually these can be removed and flushed/cleaned in a solvent such as Safety Clean.

Pittsburg Air Brake still services AB brakes for a nominal fee, and it might be prudent to spend a few hundred bucks to have it put on the test stand and fixed, if you are certain none of the hard systems under the car are at fault.

Replacing one portion with another like portion, which new part has been in storage for years and years, is no guarantee that the new one is any better than the old. And if the dirt trap is not clean, or the screens are missing, any debris or scale would quickly blow into the replacement rendering it faulty.

Bob Kutella

Has the paper filter in the pipe bracket been replaced? A dirty filter will restrict the flow and it sounds like the service portion is not charging as well as it should. Also be sure to follow the piping with a soapy water spray bottle. Those minor leaks can sure add up quickly.

A single car test can tell you an awfully lot, and more likely than not, lead you to identify your problem. Has one been performed since the components have been changed? To move the car over common carriers after changing out major components, such as portions and pipe brackets, you are supposed to do a single car test, anyway, so you probably will need the test device anyway.

G.F.Payne
Baltimore