(2) Remove the brake pipe strainer and place it
in the shipping cover. Immediately apply the cover to
the service portion and tighten the holding nuts. The
shipping cover must be applied to prevent entrance of
dirt, water, or damage to internal parts when
transporting the valve to the airbrake shop for
reconditioning (para 8-
d. Remove AB Valve Emergency Portion
(1) Remove vent protector
opening with a vent protector plug.
(2) Remove the three nuts from the mounting
studs and slide the valve portion off the studs.
Figure 8-13. Combined dirt collector and cutout
(3) Move the piston into release position and
immediately apply the shipping cover and tighten the
holding nuts. The cover must be applied to prevent
entrance of dirt, water, or damage to internal parts when
transporting the valve portion to the airbrake shop for
e. Remove Retaining Valve
(1) Unscrew the exhaust pipe from the elbow
and uncouple inlet air line at the union.
(2) Remove the nuts and bolts that secure the
valve to car end and remove valve and strainer.
(3) Place the strainer in the spare shipping
cover, then apply the shipping cover and tighten the
holding bolts. Transport the valve to the airbrake shop
f. Clean Dirt Collector. Remove nuts and bolts
that secure dirt chamber to collector body and remove
chamber from collector body. Separate gasket and
Figure 8-14. Branch pipe tee for AB brake.
check valve from the collector. Thoroughly clean
chamber and check valve of all dirt and other foreign
matter. Do not replace chamber and check valve until
after pipe bracket and associate parts have been
cleaned (G, below). When replacing check valve and
chamber, use a new gasket between chamber and body.
g. Clean Pipe Bracket and Associate Parts
(1) Using scrapers of suitable form, loosen any
dirt in the brake pipe passages, strainer chamber, and
other connecting passages of the pipe bracket.
(2) Use a blower hose with a suitable nozzle
and blow any loose dirt and scale from pipe bracket and
associate parts. Blow dirt from the face of the bracket,
strainer chamber, and branch pipe passage toward the
open dirt collector.
h. Install Reconditioned Service Portion
Figure 8-15. Sectional view of standard retaining
(1) Apply a new throw-away type or a cleaned
felt or hair type strainer to the cavity in the pipe bracket.
Use a wood mandrel to guide
Remove AB Valve Service Portion
(1) Disconnect the brake cylinder release rod.
Remove the three nuts from mounting studs and slide
the valve portion off the studs.