1
Bendix
®
SL-3
™
& SL-4
™
Stop Light Switch
SD-06-1800
FIGURE 1 - SL-3
™
STOP LIGHT SWITCH
FIGURE 2 - SL-4
™
STOP LIGHT SWITCH
DESCRIPTION
The stop light switch is an electro-pneumatic switch and
operates in conjunction with the brake valve and stop lights
by completing the electrical circuit when a brake application
is made.
OPERATION
When a brake application is made, air pressure from the
brake valve enters the cavity below the diaphragm. At
approximately 5 psi, the air pressure underneath the
diaphragm overcomes the force of the spring and moves
the piston or plunger until the contact points close completing
the stop light electrical circuit and lighting the stop lights.
PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before
performing any intrusive maintenance procedures. A warranty
may be voided if intrusive maintenance is performed during
the warranty period.
No two vehicles operate under identical conditions; as a
result, maintenance intervals may vary. Experience is a
valuable guide in determining the best maintenance interval
for air brake system components. At a minimum, the SL-3
™
/
SL-4
™
switch should be inspected every 6 months or 1500
operating hours, whichever comes first, for proper operation
and electrical connections. Should the SL-3
™
/SL-4
™
switch
not meet the elements of the operational tests noted in this
document, further investigation and service of the valve may
be required.
COVER 8
SPRING 11
CONTACT
PISTON
13
BODY
O-RING
DIAPHRAGM 14
CONTACT
STRIP 12
TERMINAL 9
VENT PLUG 10
GASKET
15
MACHINE
SCREWS
7
COVER 1
DIAPHRAGM 6
BODY
SPRING 3
CONTACTS
TERMINAL 2
PLUNGER 4
TERMINAL
CONNECTOR 7
WASHER 5
