USAFleetSupply offers a full line of
Glad Hands, Seals, Grips and accessories. Aluminum glad
hands, metal glad hand locks, universal glad hands, plastic
glad hands, single and double lip glad hand seals,
grips and more.
Browse Glad Hands, Seals and Grips Now
Hose Couplers (Glad Hands)
are coupling devices used to connect the service and
emergency air lines from the truck or tractor to the
trailer. The couplers have a rubber seal which prevents air
from escaping. Clean the couplers and rubber seals before a
connection is made. When connecting the glad hands, press
the two seals together with the couplers at a 90° angle to
each other. A turn of the glad hand attached to the hose
will join and lock the couplers.
It is very important to keep the air supply
keep the air supply clean, some vehicles have "dead end" or
dummy couplers to which the hoses may be attached when they
are not in use. This will prevent water and dirt from
getting into the coupler and the air lines. Use the dummy
couplers, if available, when the air lines are not connected
to a trailer.
To avoid mistakes, metal tags are sometimes
attached to the lines with the words service or emergency stamped
on them. Sometimes colors are used. Blue is used for the
service lines and red for the emergency lines.
If you do cross the air lines, supply air
will be sent to the service line instead of going to charge
the trailer air tanks. Air will not be available to release
the trailer spring brakes (parking brakes). If the spring
brakes don't release when you push the trailer air supply
control, check the air line connections.
Older trailers do not have spring brakes. If
the air supply in the trailer air tank has leaked away there
will be no emergency brakes and the trailer wheels will turn
freely. If you crossed the air lines, you could drive away
but you would not have trailer brakes. Before driving,
always test the trailer brakes with the hand valve or by
pulling the air supply control. Pull gently against them in
a low gear to make sure the brakes work.