TM 9-2330 -326 -14&P
SEALED BRAKE INSTALLATION AND SERVICE (Cont.)
Through one of the slot openings in the disarming chamber use an acetylene gas torch to
cut a hole (1 -1/2 to 2 inches [3.8 to 5.1 cm]) in the air brake chamber head to expose the
power coil spring. DO NOT cut the power spring. See enclosed drawing for approximate
location to cut hole on hous ing side.
Repeat the above process to the opposite side of the spring brake head. Cutting two holes
opposite each other provides the torch with sufficient oxygen for cutting the power spring.
Cutting the first power spring coil may produce a low -pitched "pop" or may cause the spring
brake chamber to jump in the disarming chamber. Repeat this cutting process through the
slot opening on the opposite side of the disarming chamber
DO NOT cut the spring brake chamber clamp bolts before
cutting the power spring coils. The spring coils MUST be cut
FIRST. If this WARNING is NOT heeded, the spring will
prematurely release 2,000 lbs of pressure, and become an
unexpected projectile that could cause injury or death to
personnel and damage to the equipment.
To make sure you have completely cut the power spring coils, use a screwdriver or similar
tool to insure that the coils are loose inside the head of the spring brake chamber.
DO NOT PLACE YOUR HANDS OR FINGERS INSIDE THE
If the coils can be moved, the spring brake chamber has been rendered safe and can be
Many manufacturers do not rebuild or condone the use of rebuilt air brake chambers. This is
because they are very impo rtant safety devices that actuate foundation brakes and perform vital
parking and emergency brake functions. Because they operate in the worst possible
environments under the most severe conditions, it is impossible to accurately determine the
condition and service life remaining in critical components such as the non-pressure housing
(mounting base), flange case (center section), power spring, and center push-rod seal. These are
all components that are typically "cleaned up" and/or repainted and reused in rebuilt actuators.
With a rebuilt actuator, you have no reliable way of knowing which components have been
replaced and how long the unit can be expected to last.
If you do not have the capability to fabricate this disarming chamber and inspect it for saf ety there
is a commercially built disarming chamber available from Jack Garner & Sons Welding which is
AWS Code welded, has positive locking, and is portable. This disarming box runs approximately
$310. They may be reached at 717 -367-2638 or 717-653 -6551, FAX: 717-367 -7906, E-Mail:
firstname.lastname@example.org . Their product "The Box #743" may be viewed at:
Chamber Fabrication: D/S and above
Disarming Procedures: Organizational and above